
From "The Civilization of Babylonia and Assyria," J. B. Lippincott Co. 

Fig. 1. — Statue of Lugal-daudu, King of Adab (3000 b.c.) Showing Eye-Sockets Lined 

with Asphalt, 

Frontispiece 



ASPHALTS 

AND 

ALLIED SUBSTANCES 

Their Occurrence, Modes of Production, 
Uses in the Arts and Methods of Testing 



BY 

HERBERT ABRAHAM 

B.S. of Chemistry, Member A.C.S., S.C.I., A.S.T.M., I.A.T.M. 



208 ILL USTRATIONS 



NEW YORK 

D. VAN NOSTRAND COMPANY 

25 Park Place 
1918 




Copyright, 1918 

BY 

D. VAN NOSTRAND COMPANY 



(?^^ 



<^ 



\ 



.i-^ 



OCT 



<il laiO: 



PRESS OF 

BRAUNWORTH & CO. 

BOOK MANUFACTURERS 

BROOKLYN, N. Y. 



lg)aA5()H24J) 



DEDICATED TO 

AS A TOKEN OF ESTEEM AND IN 
APPRECIATION OF MANY PLEASANT 
YEARS OF BUSINESS ASSOCIATION 



PREFACE 



This treatise has been written for those interested in the fabrication, 
merchandising and apphcation of bituminous products. It embraces: 
(1) methods serving as a guide for the works chemist engaged in testing 
and analyzing raw and manufactured products; (2) data for assisting 
the refinery or factory superintendent in blending and compounding 
mixtures; (3) information enabling the ambitious salesm.an to enlarge 
his knowledge concerning the scope and limitations of the articles he 
vends; and (4) the principles underlying the practical application of 
bituminous products for structural purposes, of interest to the engineer, 
contractor and architect. Subject-matter of sole value to the technical 
man has been segregated in Part V, '^ Methods of Testing," excepting 
the outline of the '^Chemistry of Bituminous Substances" appearing in 
Chapter III. These sections, however, may be passed over by the non- 
technical man, without interfering materially with the continuity of the 
work. 

In view of the vast amount of ground covered in this volume, and 
fully reahzing the limitations of his proficiency in some of its branches 
and ramifications, the author has taken it upon himself to draw freely 
from contemporary text-books and journal articles. In such instances, 
his endeavor has been to place due credit where it belongs, by referring 
to the source of such extraneous information. Nevertheless, there has 
been included a substantial amount of original data accumulated by 
the author during the past nineteen years, most of which appears in print 
herein for the first time. 

Topics which have been ably presented in other reference books, 
as for example the technology of pavements, etc., have purposely been 
subordinated to those concerning which little data has hitherto been 
available. To the latter belong such subjects as petroleum asphalts; 
fatty-acid pitches; bituminized roofings, floorings and other fabrics; bitu- 
minous paints, cements, varnishes and japans. 

Certain branches of the industry have developed along different lines 
in Europe than has been the case in this country, especially the treat- 

vii 



viii PREFACE 

ment of peat and lignite (Chapter XV), also pyrobituminous shales 
(Chapter XVI). In such instances, the methods in vogue abroad before 
the great war are described with more or less detail. It must be borne 
in mind in this connection, that the war has materially interfered with 
the prosecution of these industries abroad, and the data presented should 
be so construed, even though not specifically stated in the text. 

Whereas the greatest pains have been taken to establish the accuracy 
■of every assertion, as well as the authenticity of every alleged fact, 
the author does not flatter himself that he has escaped the pitfalls which 
must perforce beset the path of a writer who undertakes to delve into a 
subject as complicated as the one under consideration, concerning which 
there are so many divergent views. 

Appreciation is expressed for the valuable suggestions and assistance 
rendered by W. A. Hamor, D. R. Steuart, Prevost Hubbard, S. R. Church, 
E. B. Cobb, David Wesson, Clifford Richardson, S. C. Ells, and the 
author's immediate associates. 

Herbeet Abraham. 
New York City, July 1, 1918. 



TABLE OF CONTENTS 



PART I.— GENERAL CONSIDERATIONS 
CHAPTER I 

PAGE 

Historical Review 1 

Origin of the Words " Asphalt " and " Bitumen " — ^Use of Asphalt by the 
Sumerians (about 3000 to 2500 B.C.) — Use of Asphalt by the Early Persians 
(about 2800 to 2500 b.c.)— Use of Asphalt by the Early Egyptians (about 2500 
B.C.) — Use of Asphalt in Biblical Times (2500 to 1500 b.c.) — Use of Asphalt by 
the Babylonians (700 to 500 B.C.) — About 450 b.c, Herodotus of Persia — About 
430 B.C., Xenophon of Greece — About 400 b.c, Hippocrates of Greece — About 
350 B.C., Aristotle of Greece — About 250 b.c, Hannibal of Carthage — About 
80 B.C., Diodorus Siculus of Sicily — About 30 b.c, Strabo of Greece — About 25 
B.C., Marcus Vitruvius of Rome — About 60 a.d., Dioscorides of Greece — About 
100 A.D., Pliny the Elder of Rome— About 13C0 a.d., Marco Polo of Venice — 
1535, Discovery of Asphalt in Cuba — 1595, discovery of '' Pitch Lake " in Trini- 
dad by Sir Walter Raleigh — 1601, First Classification of Bituminous Substances — 
1656, Early Dictionary Definition of '* Bitumen " — 1661, Com.m.ercial Production 
of Wood Tar — 1672, First Accurate Description of Persian Asphalt Deposits 
— 1873, Discovery of Elaterite — '1681, Discovery of Coal Tar and Coal-tar Pitch — 
1691, Discovery of Illuminating Gas from Coal — 1694, Discovery of Shale Tar and 
Shale-tar Pitch — 1712-30, Discovery of Val de Travers, Lim-m.er and Seyssel 
Asphalt Deposits — 1746, Invention of the Process of Refining Coal Tar — 1777, 
First Exposition of Modern Theory of the Origin of Asphalt — 1788, Discovery of 
Lignite Tar — 1790-1800, Discovery of " Composition " or " Prepared " Roofing — 
1792-1802, Manufacture of Coal Gas and Coal Tar on a Large Scale— 1797-1802, 
Exploitation of Seyssel Asphalt in France — 1815, Comm.ercial Exploitation of 
Coal-tar Solvents — 1822, Discovery of Scheererite and Hatchettite — 1830, Dis- 
covery of Paraffine Wax — 1833, Discovery of Ozokerite — 1836, Asphalt First 
Used in London for Foot Pavements — 1837, Publication of First Exhaustive 
Treatise on the Chemistry of Asphalt — 1838, Discovery of Process for Preserving 
Wood with Coal-tar Creosote — 1838, Asphalt First Used in the United States 
for Foot Pavements — 1842, Discovery of Bituminous Matter in the United 
States — 1843, Bituminous Matters Discovered in New York State — 1850, Dis- 
covery of " Asphaltic Coal " in New Brunswick, Nova Scotia — 1854, First Com- 
pressed Asphalt Roadway Laid in Paris — 1858, First Modern Asphalt Pavement 
Laid in Paris — 1863, Discovery of Grahamite in West Virginia — 1869, The First 
Compressed Asphalt Pavement in London — 1870-1876, First Asphalt Roadways in 

ix 



X CONTENTS 

PAGE 

the United States — 1879, First Trinidad Asphalt Pavement Laid in the United 
States — 1881, Use of Chemicals for Oxidizing Coal Tars and Petroleum Asphalts — 
1885, Discovery of Uintaite (Gilsonite) in Utah — 1889, Discovery of Wurtzilite in 
Utah — 1891, Exploitation of the Bermudez Asphalt Deposit, Venezuela — 1894, 
Use of Air for Oxidizing Petroleum Asphalt. 



CHAPTER II 
Terminology and Classification of Bituminous Substances ... 19 

Bituminous Substances — Bitumen — Pyrobitumen — Petroleum — Mineral Wax — 
Asphalt — Asphaltite — Asphaltic Pyrobitumen — Non-asphaltic Pyrobitumen — Tar 
—Pitch. 



CHAPTER III 

Chemistry of Bituminous -Substances 28 

Structural Formulas of the Most Important Pure Chemical Substances Present 
in Bituminous Complexes — Oyen Chain Hydrocarbons — CnH2n+2 Series, Saturated, 
Single Bonds, " Paraffines " — CnH^n Series, Unsaturated, One Double Bond, 
" Olefines " — CnH n-2 Series, Unsaturated, One Triple Bond, " Acetylenes " — 
CnH2n— 2 Series, Unsaturated, Two Double Bonds, " Diolefines " — CnH2n-4 
Series, Unsaturated, One Double and One Triple Bond, '' Olefinacetylenes " — 
CnH2n-4 Series, Unsaturated, Three Double Bonds, " Poly olefines " — CnH^n-e 
Series, Unsaturated, Two Triple Bonds, '' Diacetylenes " — Cyclic Hydrocarbons — 
CnH2n Series, Saturated, Single Bonds, MonocycHc, " Naphthenes," also called 
" Cycloparaffines " or " Polymethylenes " — CnH2n-2 Series, Saturated, Single 
Bonds, Polycychc, " Polycychc Polymethylenes " — CnH2n-2 Series, Unsaturated, 
One Double Bond; Monocyclic, '' Cyclo-Olefines " — CnH2n-4 Series, Unsaturated, 
Two Double Bonds, Monocyclic, '' Terpenes " — CnHi;n-4 Series, Saturated, Single 
Bonds, " Polycychc Polynaphthenes " — CnH2n-6 Series, Unsaturated, Three 
Double Bonds, Monocychc, " Benzenes " — CnH2n-8 to CnHgn-so Series, Unsatu- 
rated, Monocyclic and Polycychc — Oxygenated Bodies — Nitrogenous Bodies — 
Sulphurated Bodies — Percentages of the Elements Present in Bituminous Sub- 
stances. 



CHAPTER IV 
Geology and Origin of Bitumens and Pyrobitumens 46 

Geology — Age of the Geological Formations — Character of the Associated Min- 
Qr^olg — Modes of Occurrence — Springs — Lakes — Seepages — Subterranean Pools or 
Reservoirs — Impregnated Rock in Strata — Filling Veins — Movement of Bitumens 
in the Earth's Strata — Hydrostatic Pressure — Gas Pressure — Capillarity — Gravi- 
tation—Effect of Heat— Origin and Metamorphosis of Bitumens and Asphaltic 



CONTENTS xi 

PAGE 

Pyrobitumens — Probable Origin of Bitumens and Asphaltic Pyrobitumens — 
Inorganic Theories — Vegetable Theories — Animal Theories — INIetamorphosis of 
Mineral Waxes, Asphalts, Asphaltites and Asphaltic Pyrobitumens from Petroleum 
— Origin and Metamorphosis of Non- Asphaltic Pyrobitumens. 



CHAPTER V 

Annual Production of Asphalts, Asphaltites and Asphaltic 
Pyrobitumens 62 

World Production — Production in United States — Production by States — 
Imports — Exports — Consumption of Asphalt in the United States. 



PART n.— SEMI-SOLID AND SOLID NATIVE BITUMINOUS 

SUBSTANCES 

CHAPTER VI 

Methods of Refining 68 

Dehydration — Sedimentation — Extraction by Means of Water — Extraction 
"uith Solvents. 

CHAPTER VII 

Mineral Waxes 74 

Ozokerite — Galicia — Rumania — Russia — United States — Hatchettite or 
Hatcheltine — Scheererite — Kabaite — Montan Wax. 

CHAPTER VIII 

Native Asphalts Occurring in a Fairly Pure State 82 

North AcLerica — United States — Kentucky — Oklahoma — Utah — California — 
Oregon — Mexico — State of Tamaulipas — State of Vera Cruz — Cuba — Province of 
]\Iatanzas — South America — Venezuela — State of Bermudez — State of Zulia 
— Europe — France — Department of Puy-de-D6me — Albania — Selenitza — Greece — 
Zante — Asia — Syria — Eastern Siberia — Sakhahn — Phihppine Islands — Island of 
Leyte. 



xii CONTENTS 

CHAPTER IX 

PAGE 

Native Asphalts Associated with Mineral Matter 92 

North America — United States — Kentucky — Missouri — Indiana — Oklahoma 
— Louisiana — Texas — Utah — Cahfornia — Canada — Alberta — Mexico — Cuba 
— Province of Matanzas — Province of Pinar del Rio — Province of Havana — Prov- 
ince of Camaguey — South America — Trinidad — Argentine — Province of Jujuy 
— Province of Chubut — Europe — France — Department of Landes — Department of 
Card — Department of Haute-Savoie — Department of Ain — Switzerland — Alsace- 
Lorraine — Germany — Province of Hanover — Province of Westphalia — Province of 
Hessen — Austria — Province of Dalmatia — Province of Tyrol — Province of Bihar 
— Province of Herzegovina — Italy — Compartment of Marches — Compartment of 
Abruzzi ed Molise — Compartment of Calabria — Compartment of Campania — 
Compartment of Sicily — Greece — District of Triphily — Portugal — Province of 
Estremadura — Spain — Province of Santander — Province of Alava — Province of 
Navarre — Province of Tarragona — Province of Soria — Russia— Frovince of Terek 
— Province of Simbirsk — Asia — Japan — Ugo Province — Asiatic Russia — Province 
of Uralsk — Syria — Mesopotamia-^ Arabia — Africa — Algeria — Province of Oran — 
Nigeria — Rhodesia. 

CHAPTER X 

ASPHALTITES 127 

Gilsonite or Uintaite — United States — Utah — Glance Pitch — Mexico — Chapa- 
pote — West Indies — Barbados — Santo Domingo (Hayti) — Colombia — (South 
America) — Syria — Hasbaya — Dead Sea — Egypt — Grahamite — United States — 
West Virginia — Texas — Oklahoma — Colorado — Mexico — Province of Vera Cruz — 
Province of Tamaulipas — Ciiba — Province Pinar del Rio — Province of Havana — 
Province of Santa Clara — Trinidad. 

CHAPTER XI 

AsPHALTic Pyrobitumens . 149 

Elaterite — England — Derbyshire County — Australia — State of South Aus- 
traha — Asiatic Russia — Province of Semiryechensk — ^Wurtzilite — United States — 
Utah — Albertite — Canada — Province of New Brunswick — Province of Nova 
Scotia — United States — Utah — A ustralia — Tasmania — West Africa — Libollo — 
Impsonite — United States — Oklahoma — Arkansas — Nevada. 

CHAPTER XII 

Pyrobituminous Shales 158 

Torbanite — Pyropissite — United States — Canada — Province of New Brunswick 
— Province of Nova Scotia — Province of Newfoundland — Province of Quebec — 



CONTENTS xiii 

PAGE 

Brazil — Province of Bahia — England — Scotland — Germany — Spain — Austria — 
Australia — New South Wales — New Zealand — Tasmania — Queensland — Victoria. 



PART III.— TARS AND PITCHES 



CHAPTER XIII 
General Methods of Producing Tars 165 

Destructive Distillation — Composition of the Substance — The Temperature — 
The Time of Heating — The Pressure — Upon the Efficiency of the Condensing System 
— Partial Combustion with Air and Steam — Partial Combustion with a Limited 
Access of Air — Cracking of Oil Vapors — Methods of Separating Tars — Condensers — 
Hydraulic Main — Air-condensers — Water-condensers — Static Scrubbers — Rain 
Scrubbers — Hurdle Scrubbers — Baffle Scrubbers — Mechanical Scrubbers — Feld 
Centrifugal Scrubber — Reading Centrifugal Scrubber — Thiesen Centrifugal 
Scrubber — Schwarz-Bayer Disintegrator — Deflectors — P. & A. Tar Extractor — 
Centrifugal Deflector — Filters — Smith Tar Extractor — Electrical Precipitators — • 
Cottrell System — Methods of Dehydrating Tars — Settling Tanks — Baffle-plate 
Separator — Heating Quietly under Pressure — Wilton Process — Heating a Thin 
Stream under Vacuum — Centrifugal Method— Electrical Method — Feld System 
of Fractional Coohng. 



CHAPTER XIV 

Wood Tar, Wood-Tar Pitch and Rosin Pitch 184 

Wood Tar and Wood-Tar Pitch — Varieties of Wood Used — Yields of Dis- 
tillation — Hardwood Distillation — Retorts — Method of Distilling — Refining Proc- 
esses — Soft (Resinous) Wood Distillation — Retorts — Method of Distfllation — 
Refining Processes — " Stockholm Tar " — Physical and Chemical Characteristics of 
Hardwood Tar and Pine Tar — Physical and Chemical Characteristics of Hardwood- 
Tar Pitch and Pine-Tar Pitch— Rosin Pitch— Raw Materials Used— Stifl Used- 
Methods of Distillation — Products Obtained — Physical and Chemical Character- 
istics of Rosin Pitch — " Burgundy Pitch." 



CHAPTER XV 

Peat and Lignite Tars and Pitches 197 

Peat Tar and Peat-Tar Pitch — Formation of Peat — Varieties of Peat — Char- 
acteristics of Peat — Methods of Collecting — Dehydrating Processes — Methods of 
Distillation — Ziegler Process — Destructive Distillation and Yields — Utilization of 
Peat for Manufacturing Producer Gas — Properties of Peat Tar — Production of 



Xiv CONTENTS 

PAGE 

Peat-Tar Pitch — Lignite Tar and Lignite-Tar Pitch — Varieties of Lignite Available 
— Kinds Suitable for Distillation — Mining Methods — Retorts Used — Products 
Obtained on Destructive Distillation and Yields — Methods of Treating Impure 
Lignite — Use of Lignite for Manufacturing Producer Gas — Properties of Lignite 
Tar — Refining of Lignite Tar — Stills Used — Refined Products Obtained and Their 
Yields — Methods of Purification — Production of Lignite-Tar Pitch — Properties of 
Lignite-Tar Pitches. 



CHAPTER XVI 

Shale Tar and Shale-Tar Pitch 216 

Shale Mining — Retorts Used for Distillation — Pumpherston Retort — Young 
& Fyfe Retort — Henderson Retort — Del Monte Retort — Methods of Recovering 
Shale Tar — Products Obtained and their Yields — Properties of Shale Tar — 
Refining of Shale Tar — Products' Obtained — Methods of Purification. 



CHAPTER XVII 
Coal Tar and Coal-Tar Pitch 225 

Bituminous Coals Used — Chemical Composition of Coals — Production of Gas- 
Works Coal Tar — Retorts Used — Methods of Recovery— Products Obtained and 
Their Yields — Production of Coke-Oven Coal Tar — Annual Production — Semet- 
Solvay Coke-Oven — Otto-Hoffman Coke-Oven — ^United-Otto Coke-Oven — Koppers 
Coke-Oven — Production of Blast-Furnace Coal Tar — Methods of Recovery and 
Yields — Production of Producer-Gas Coal Tar — Tj^pes of Producers Used — Prop- 
erties of Coal Tars — Properties of Gas- Works Coal Tar, Coke-Oven Coal Tar, 
Blast-Furnace Coal Tar and Producer-Gas Coal Tar — Refining of Coal Tar — 
Stills Used — Distillation Products and their Yields — Continuous Distillation Proc- 
esses — Feld Fractional Condensing System — Commercial Varieties of Coal Tar 
and Coal-Tar Pitch — Properties of Coal-Tar Pitches — Properties of Gas- Works Coal- 
Tar Pitch, Coke-Oven Coal-Tar Pitch, Blast-Furnace Coal-Tar Pitch and Pro- 
ducer-Gas Coal-Tar Pitch. 



CHAPTER XVIII 

Water-Gas and Oil-Gas Tars and Pitches 256 

Water-gas Tar — Method of Production — Yields — Properties of Dehydrated- 
Water-Gas Tar — Oil-Gas Tars — Methods of Production — Pintsch Gas — Oil- 
Water Gas — Blau Gas — Properties of Oil-Gas Tars. Refining of Water-Gas 
and Oil-Gas Tars — Properties of Water-Gas- Tar Pitch and Oil-Gas- Tar Pitch. 



CONTENTS XV 

CHAPTER XIX 

PAGE 

Petroleum Asphalts 265 

Varieties of Petroleum — Products Obtained from Petroleum — Distillates — 
Gasoline — Naphtha — Kerosene — Gas or Fuel Oil — Lubricating Oil — Paraffine Wax 
— Wax Tailings — -Residues — Residual Oil — Residual Asphalt — Blown Asphalt — 
Sulphurized Asphalt — Sludge Asphalt — Coke — Petrolatum — Dehydration of 
Petroleum — Settling — Heating under Pressure — Milliff Hot- Air System — Elec- 
trical Method — Methods of Refining PetTolenmr— Intermittent Distillation Proc- 
esses — Dry Distillation — Steam Distillation — Continuous Distillation Processes — 
Topping Process — Livingston Process — Steam Distillation of Asphalt-Bearing 
Petroleum — Process Used — Products Obtained and their Yields — Steam Distillation 
of Non-Asphaltic and Mixed-Base Petroleums — Process Used — Products Obtained 
and Their Yields — Dry Distillation of Non-Asphaltic and Mixed- Base Petroleums — 
Process Used — Products Obtained and Their Yields — Residual Oils — Varieties 
Obtained — Physical and Chemical Characteristics — Blown Asphalts — Processes 
L^sed — Advantages of " Blowing " Over the Steam-Distillation Process — Physical 
and Chemical Characteristics — Sulphurized Asphalts — Residual Asphalts — Proc- 
esses Used — Physical and Chemical Characteristics — Methods of Distinguishing 
Between Petroleum Asphalts and Native Asphalts — Sludge Asphalts — Methods 
of Production — Physical and Chemical Characteristics. 

CHAPTER XX 

Paraffine Wax and Wax Tailings 307 

Paraffine Wax — Sources from which Obtained — Methods of Production — 
Refining Processes — Physical and Chemical Characteristics — Wax Tailings — 
Methods of Production — Physical and Chemical Characteristics. 

CHAPTER XXI 

Wurtzilite Asphalt 313 

Method of Production — Still Used — Depolymerization Process — Grades of 
Wurtzilite Asphalt Produced — Chemical and Physical Characteristics. 

CHAPTER XXII 

Fatty-Acid Pitch, Bone Tar and Bone-Tar Pitch 317 

Fatty-Acid Pitch — Sources from which Obtained — Production of Candle and 
Soap Stocks — Hydrolysis by Means of Water — Hydrolysis by Means of Concen- 
trated Sulphuric Acid — Hydrolysis by the " Mixed Process " Hydrolysis by 
Means of the Sulpho-Compounds — Hydrolysis by Means of Ferments — Refining 
Vegetable Oils by Means of Alkali — Refining of Cotton-Seed Oil — Refining of Corn- 



xvi CONTENTS 

PAGE 

Oil — Refining Refuse Greases — Refining Packing-House and Carcass-Rendering 
Greases— Refining Bone Grease — Refining Garbage and Sewage Greases — Refining 
Woolen-Mill Waste — Treatment of Wool Grease — Physical and Chemical Prop- 
erties of Fatty-Acid Pitches — Bone Tar and Bone-Tar Pitch — Methods of Pro- 
duction — Physical and Chemical Characteristics. 

PART IV.— MANUFACTURED PRODUCTS AND THEIR USES 

CHAPTER XXIII 

Methods of Blending 338 

Hardness, Fusibility, Approximate Comparative Volatility, Weatherproof 
Properties and Efficiency of Fluxing of Various Bituminous Substances — Prin- 
ciples Involved in Preparing Mixtures — Binary Mixtures — Softening of the Sub- 
stance and Lowering its Fusing-Point — Hardening the Substance and Raising its 
Fusing-Point — Rendering the Mixture Less Susceptible to Temperature Changes — 
Effecting a More Perfect Union or Blending of the Constituents — Making the 
Mixture more Weatherproof — ^Increasing the Tensile Strength of the Mixture — 
Rendering Wax-Like, Unctuous to the Feel, or Lessening the Tendency towards 
Stickiness — Tertiary and Complex Mixtures — Classes of Bituminous Mixtures — Soft 
(Liquid) bituminous products — Medium (Semi-solid) Bituminous Products — Hard 
(Solid) Bituminous Products — Processes of Blending Bituminous Substances — Appa- 
ratus for Incorporating Fillers — Emulsification. 

CHAPTER XXIV 
Bituminous Paving Mateeials 352 

Bituminous Dust-Laying Oils — Bituminous Materials Used — Bituminous 
Emulsions — Non-Emulsified Products — General Considerations — Methods of Us-e 
— Bituminous Surfacings — Bitimiinous Binder — Mineral Aggregate — Preparing 
and Applying the Surfacing — General Considerations — Bituminous Macadam — 
Foundation Course — Mineral Aggregate — Bituminous Binder — Preparing and 
Applying the Surface Course — Bituminous Concrete Pavements — Foundation or Base 
Course — Mineral Aggregate — ^Bituminous Cement or Binder — Preparing and 
Applying the Mixture — General Considerations — Sheet Asphalt Pavements — 
Foundation or Base Course — Intermediate or Binder Course — Surface or Wearing 
Course — Asphaltic Cement — Preparing and Applying the Wearing or Surface 
Course — Asphalt Block Pavements — Foundation or Base — Laying the Blocks — 
Asphalt Mastic Foot- Pavements and Floors — Asphalts Used — Methods of Prepara- 
tion — Methods of Laying — Bituminized Wood-Block Pavements — Methods of 
Impregnation — Creosote Preservatives — Foundation Course — Cushion Layer — 
FilHng the Joints — General Considerations — Bituminous Fillers for Wood, Brick 
and Stone Pavements — Characteristics of Bituminous Materials Used — Filling the 
Joints— Bituminous Expansion Joints — Premoulded Strips — Bituminized Fabric 
Strips — Armored Bituminized Fabrics. 



CONTENTS xvii 

CHAPTER XXV 

PAGE 
BiTUMINIZED FaBEICS FOR ROOFING. FLOORING, WATERPROOFING 

Sheathing and Insulating Purposes 386 

Sheet Roofings — Felted Fabrics — Woven Fabrics — Bituminous Saturating 
Compositions — Bituminous Coating and Adhesive Compositions — Surfacings of 
Mineral Matter — Surfacings of Vegetable Matter — Saturating the Fabric — Single- 
layered Prepared Roofings — Laminated Prepared Roofings — Roll Roofings Fin- 
ished with an Ornamental Surface — Prepared Roofing Shingles — Fastening 
Devices — Methods of Forming Roll Roofing Packages — Methods of Laying Pre- 
pared Roofings and Shingles — Rating of Prepared Roofings and Shingles by the 
L^nderwriters Laboratories, Inc. — Bituminized Floor Coverings — Methods of 
Maniifacture — Method:: of Printing and Graining — Waterproofing Membranes — • 
Materials Used — Preparing the Underlying Surface — Selecting and Installing the 
Waterproofing Membrane — Protecting the Waterproofing Membrane — Insulat- 
ing and Sheathing Papers — Raw Paper Stock — Bituminous Saturation — Bitu- 
minous Coating Compositions — Method of Manufacture — Efficiency of the Paper — • 
Saturated and Coated Papers for Electrical Insulation — Electrical Insulating 
Tape — Characteristics of the Bituminous Impregnation — Bituminized Wall Board 
— Method of Manufacture 

CHAPTER XXVI 

Semi-Liquid, Semi-Solid and Solid Bituminious Compositions .... 442 

Adhesive Compounds for Built-Up Roofing and Waterproofing Work — Adhesive 
Compounds for Membrane Waterproofing Underground — Adhesive Compounds for 
Membrance W^aterproofing Above Ground — Adhesive Compounds for Built-Up 
Roofing Work — Pipe Dips and Pipe-Sealing Compounds — Pipe Dips — Pipe-Sealing 
Compounds — Electrical Insulating Compounds — Insulation for Cotton-Covered 
Transmission Wires — Vacuum Impregnating Compounds — Jimction-box and Pot- 
head Compounds — Battery-box Compounds — '' Carbons " for Batteries, Electric 
Lights and Armature Brushes — Bituminous Rubber Substitutes — Moulding Com- 
positions — Mixtures for Small Moulded Articles — Preformed Joints and Washers — 
Bituminated Cork Mixtures — Bituminated Leather Mixtures — Briquette Binders — 
Core Compounds — Miscellaneous Bituminous Products — Bituminous Fuels — Tars 
and Oils for the Flotation of Ores — Wood Preservatives — Waterproofing Com- 
pounds for Portland-Cement Mortar and Concrete — Pure Bituminous Materials — 
Bituminous Materials in Emulsified Form — Methods of Use. 



CHAPTER XXVII 

Bituminous Paints, Cements, Varnishes, Enamels, and Japans 462 

Bituminous Paints — Nature of the Base Used — Nature of the Fillers and Pig- 
ments Used — Nature of the Solvents Used — Methods of Manufacture — Types of 



xviii CONTENTS 

PAGE 

Bituminous Paints — Masonry Paints — Paints for Recoating Prepared Roofings — 
Bituminous Paints for Metal or Wood — Bituminous Cements — Method of Prepara- 
tion — Method of Use — Bituminous Varnishes — Method of Manufacture — Bitu- 
minous Enamels — Method of Manufacture — Bituminous Japans — Method of 
Preparation and Use. 



PART v.— METHODS OF TESTING 



CHAPTER XXVIII 

Physical Characteristics 480 

Synoptical Table of Bituminous Substances — Color in Mass — Homogeneity — 
To the Eye at 77° F. — Under Microscope — When Melted — Appearance Surface 
Aged Indoors One Week — Fracture — Lustre — Streak on Porcelain — Specific Gravity — ■ 
Hydrometer Method for Fluid Materials — Westphal Balance Method^Pycnometer 
Method — Sommer Hydrometer Method — Hubbard Pycnometer Method — Weiss' 
Specific Gravity Pan Method — Viscosity — Engler Method — Hutchinson's Tar 
Tester — Hubbard's Consistency Tester — Float Test — Schutte Consistency Tester 
— Hardness or Consistency — Moh's Hardness Scale — Needle Penetrometer — 
Consistometer — Susceptibihty Factor — Ductility — Dow Ductihty Test — Author's 
DuctiUty Test — Tensile Strength — Adhesiveness Test — Osborne Adhesive Test — 
Kirschbraun Adhesive Test. 



CHAPTER XXIX 

Heat Tests 509 

Odor on Heating — Subjection to Heat — Behavior on Melting — Behavior on 
Heating in Flame — Fusing {" Melting-Point ") — Kramer-Sarnow Method — Ball 
and Ring Method — Cube Method — Flowing Temperature — Volatile Matter — ■ 
Flash-Point — Pensky-Martens Closed Tester — Cleveland Open Tester — New York 
State or Elliot Closed Tester — Burning-Point — Fixed Carbon — Distillation Test — 
Flask Method of Distillation — Retort Method of Distillation. 



CHAPTER XXX 

Solubility Tests 524 

Solubility in Carbon Disulphide — Soluble in Carbon Disulphide — Non-Mineral 
Matter Insoluble in Carbon Disulphide — Mineral Matter — Carbenes — Solubility 
in 88° Petroleum Naphtha — Solubility in Other Solvents. 



CONTENTS xix 

CHAPTER XXXI 

PAGE 

Chemical Tests 529 

Water — Substances Distilling at Low Temperatures — Substances Distilling 
at High Temperatures — Carbon — Hydrogen — Sulphur — Nitrogen — Oxygen — Free 
Carbon in Tars — Naphthalene in Tars — Solid Paraffines — Saturated Hydrocarbons 
— Sulphonation Residue — Mineral Matter — Uncombined Mineral Matter — Mineral 
Matter Combined with Non-]\Iineral Constituents — Chemical Analysis of Mineral 
Matter — Microscopic Examination — Granularmetric Analysis — Specific Gravity 
of Mineral Matter — Saponifiable Constituents — Free Acids (Acid Value) — Lactones 
and Anhydrides (Lactone Value) — Neutral Fats (Ester Value) — Saponification 
Value — Estimation of Fatty and Resin Acids — Asphaltic Constituents — Free 
Asphaltous Acids — Asphaltous Acid Anhydrides — Asphaltenes — Asphaltic Resins 
— Oily Constituents — Estimation of Unsaponifiable and Saponifiable Matters — 
Hydrocarbons — Higher Alcohols (Cholesterol) — Glycerol — Diazo Reaction — Anthra- 
quinone Reaction — Liebermann-S torch Reaction. 

CHAPTER XXXII 

Methods of Testing Manufactured Products 552 

Bituminized Mineral Aggregates — Effect of Moisture — Tensile Strength — 
Compressive Strength — Transverse Strength — Impact Test — Distortion under 
Heat — Softening-point — Separation of the Bituminous Matter and Mineral 
Aggregate — Forrest's Hot Extraction Method — Centrifugal Method — Recovery 
of Extracted Bituminous Matter — Examination of the Recovered Mineral 
Aggregate. Bituminized Fabrics — Physical Tests of the Finished Fabric — Plia- 
bility Tests — Heating Tests — Separating Prepared Roofing into Its Component 
Parts — Mineral Matter — Bituminous Matter — Fibrous Matter — Testing the Raw 
Felt — Ash — Fibres Present — Number — Thickness — Mullen Strength — Testing the 
Raw Burlap or Du£k — Weight — Thickness — Strength — Testing the Bituminous 
Compounds — Examining the Mineral Ingredients — Bituminous Emulsions — Bitu- 
minous Paints, Cements, Varnishes and Japans — Estimation of Solvent — Pigment 
and Filler — Examination of the Base — Analyzing the Base — Examining Dry Paint 
FHms. 

CHAPTER XXXIII 

Weathering Tests 574 

Effects of Weathering — Evaporation — Oxidation — Carbonization — Polymeriza- 
tion — Effects of Moisture — Conducting Weathering Tests on Bituminized Fabrics — 
Conducting Weathering Tests on Bituminous Paints. 



ILLUSTRATIONS 



FIG. PAGE 

1. Statue of Lugal-daudu, King of Adab (3000 b.c.) Sho^^ng Eye-sockets Lined 

with Asphalt Frontispiece 

2. Human-Headed Bull (3000 b.c.) with Shells Inlaid in Asphalt 2 

3. Heraldic Device of Lagash (2850 b.c.) Case in Asphalt 3 

4. Bust of Manishtusu, King of Kish (2600 b.c.) with Eyes Set in Asphalt 4 

5. Libation Vase Dedicated to Gudea, Ruler of Lagash (2500 b.c.) Showing Shells 

Set in Asphalt 5 

6. Early Persian Sculpture with E5'es Set in Asphalt 5 

7. Persian Vases He\^^l from Blocks of Asphalt 6 

8. Primitive Animal Carved from Asphalt 6 

9. Asphalt Spring in ]\Iesopotamia 9 

10. Floor of Nebuchadnezzar's Temple as it Appears To-day, Showing Blocks 

Joined by Means of Asphalt 10 

11. Trilinear Coordinates on an Equilateral Triangle 43 

12. Trilinear Coordinates on an Isosceles Triangle 43 

13. Percentages of Carbon, Hj'-drogen and Oxygen in Typical Bituminous Sub- 

stances 44 

14. Asphalt Spring 49 

15. Asphalt Lake 49 

16. Asphalt Seepage 49 

17. Subterranean Pool or Reservoir 49 

18. Asphalt-Impregnated Horizontal Strata 49 

19. Asphalt -Impregnated Strata in Thrust 49 

20. Fault Filling Caused by Cleavage 49 

21. Fault Filling Caused bj^ Upturning 49 

22. Vein Filhng Caused by SUding of Strata 49 

23. Veins Formed by Sedimentation 49 

24. Production of Asphalts and Asphaltites in the U. S. from 1880 to 1916 65 

25. Steel IMelting Tank 69 

26. Apparatus for Separating Soft Asphalt from Sand by Means of Water 72 

27. Looking into the Top of the Extracting Apparatus 73 

28. View of Bermudez Asphalt Lake 87 

29. Transporting Bermudez Asphalt 87 

30. Map of Asphalt Region in Oklahoma 94 

31. Sand Asphalt Quarries in Santa Cruz County, Cal 103 

32. Sand Asphalt Quarries in Santa Cruz County, Cal 104 

33. Asphaltic Sand on the Shore at Carpenteria, Cal 105 

34. Asphaltic Sand on Banks of Athabaska River, Alberta, Can 106 

xxi 



xxii ILLUSTRATIONS 

FIG. PAGE 

35. Map of Trinidad Asphalt Lake 109 

36. Panoramic View of Trinidad Lake 110 

37. Folds in the Surface of Trinidad Lake Ill 

38. Evolution of Gas from Trinidad Lake Ill 

39. Gathering Trinidad Lake Asphalt 112 

40. Transporting Trinidad Lake Asphalt 112 

41. Map of Seyssel Asphalt Deposit, France 117 

42. Map of Neuchatel (Val-de-Travers) Asphalt Region, Switzerland 118 

43. Map of Lobsann Asphalt Region, Alsace-Lorraine 119 

44. Cross-Section of Limmer Asphalt Deposit Germany 120 

45. Chart of Physical Characteristics of Fluxed Gilsonite Mixture 129 

46. Faults in Gilsonite Vein 130 

47. Map of Gilsonite Region, Utah 131 

48. View of Cowboy Gilsonite Mine, Utah 132 

49. Vertical Section through Dead Sea Showing Glance Pitch Veins 136 

50. View of Grahamite Vein, Ritchie County, W. Va 138 

51. Sections through Grahamite Mine, Ritchie County, W. Va 139 

52. Vertical Section'through Grahamite Mine near Tuskahoma, Okla 140 

53. Chart of Physical Characteristics of Fluxed Oklahoma Grahamite Mixture. . . . 141 

54. Chart of Physical Characteristics of Fluxed Trinidad Grahamite Mixture 148 

55. View of Wurtzilite Mine, Uinta County, Utah 151 

56. Transporting Wurtzilite from the Mine 152 

57. Vertical Section through Wurtzilite Vein, Uinta County, Utah 152 

58. Hydraulic Main 174 

59. Air Condenser 175 

60. Water Condenser 175 

61. Rain Scrubber 176 

62. Hurdle Scrubber Filled with Coke 176 

63. Hurdle Scrubber Filled with Wooden Slats 176 

64. Baffle Scrubber 176 

65. Feld Centrifugal Scrubber 177 

66. Reading Centrifugal Scrubber 177 

67. Thiesen Centrifugal Scrubber 178 

68. Schwarz-Bayer Disintegrator 179 

69. P. & A. Tar Extractor 179 

70. Centrifugal Deflector 179 

71. Smith Tar Extractor 179 

72. Cottrell Electrical Precipitator 180 

73. Baffle-Plate Tar Separator 181 

74. Centrifugal Tar Dehydrator 182 

75. Iron Cars Used in the Distillation of Hardwood 186 

76. Modern Wood Distilling Plant 187 

77. Plant for Refining Wood Tar 187 

78. Retorts for Distilling Soft Wood 189 

79. Retort for Distilling Rosin 193 

80. Korting Double-Zone Up-Draf t Gas Producer for Peat 202 

81. Retort for Distilling Pure Lignite 206 

82. Retort for Distilling Impure Lignite 208 



ILLUSTRATIONS xxiii 

FIG. PAGE 

83. Young & Beilby Retort for Distilling Shales 217 

84. Pumpherston Retort for Distilling Shales 218 

85. Henderson Retort for Distilling Shales 219 

86. Horizontal Gas- Works Retort 228 

87. Inclined Gas- Works Retort 229 

88. Vertical Gas-Works Retort 230 

89. Semet-Solvay Coke Oven 235 

90. Otto-Hofifman Coke Oven 236 

91. United-Otto Coke Oven 237 

92. Koppers Coke Oven 237 

93. Blast-Furnace Dust Catcher 238 

94. Fairbanks-Morse Suction Gas-Producer, Type 1 241 

95. Loomis-Pettibone Section Gas-Producer, Type 2 241 

96. Westinghouse Gas-Producer, Type 3 242 

97. Horizontal Still for Refining Coal Tar 247 

98. Vertical Still for Refining Coal Tar 247 

99. Feld System for Fractioning Coal Tar 249 

100. Chart of Physical Characteristics of Coal-Tar Pitch 254 

101. Lowe Water-Gas Plant 256 

102. Pintsch Gas Retort 260 

103. Oil- Water Gas Plant 260 

104. Plant for Dehydrating Petroleum 270 

105. Horizontal Petroleum Stills 271 

106. Plant for Refining Petroleum 272 

107. Tower System for Distilling Petroleum 273 

108. Topping Plant for Refining Petroleum 275 

109. Livingston Apparatus for Continuous Distillation of Petroleum 276 

110. Effect of Blowing on the Fusing-Point and Hardness of Petroleum Asphalt . . 290 

111. Chart of Physical Characteristics of Blown Petroleum Asphalt 291 

112. Relation between the Specific Gravity and Fusing-point of Residual Oils, 

Blown Petroleum Asphalts and Residual Asphalts 293 

113. Chart of Physical Characteristics of D-Grade California Asphalt 302 

114. Apparatus for the Acid-Purification of Petroleum Distillates 303 

115. Paraffine Wax Sweater 308 

116. Mixer for Incorporating Large Percentages of Fillers in Asphalt 351 

117. Mixer for Preparing Paving Compositions 372 

118. Tools for Finishing Mastic Floors 376 

119. Machine for Manufacturing Roofing Felt 387 

120. Tar Saturator : 396 

121. Asphalt Saturator 396 

122. Prepared Roofing Finished in a Veined Surface 400 

123. Prepared Roofing Finished with Coarse Talc 400 

124. Prepared Roofing Finished with Fine Sand 400 

125. Prepared Roofing Finished with Crushed Slate 400 

126. Prepared Roofing Finished with Crushed Feldspar 400 

127. Prepared Roofing Finished with Pebbles 400 

128. Coating Machine Used in the Intermittent Process of Manufacturing Roofing 404 

129. Continuously Operating Machine for Manufacturing Prepared Roofing 404 



xxiv ILLUSTRATIONS 

FIG. PAGE 

130. Device for Applying Mineral Particles to the Surface of Prepared Roofing 406 

131. Winding Mechanism 406 

132. High-Speed Continuously Operating Machine for Manufacturing Prepared 

Roofing 407 

133. Machine for Assembling Multiple-Layered Bituminized Fabrics 410 

134. Roll Roofings Finished in an Ornamental Surface 411 

135. Shingle Cutter (Front View) 413 

136. Shingle Cutter (Rear View) 413 

137. Wide-Spaced Shingles 414 

138. Multiple Shingle Strip 414 

139. Diamond Shingle Strip 415 

140. Reversible Shingle Strip 415 

141. Types of Roofing "Cleats" 417 

142. Wire Roofing Fastener 417 

143. Laying Roll Roofing in Single Course 419 

144. Two-Ply Built-Up Roofs over Wood and Concrete 420 

145. Three-Ply Built-Up Roofs over Wood and Concrete 421 

146. Five-Ply Built-Up Roofs over Wood and Concrete 422 

147. Laying Individual Shingles 423 

148. Chart of Annual Production of Roofings in the U. S 425 

149. Vacuum Impregnating Apparatus 450 

150. Preformed Washers for Skylights 453 

151. Varnish Kettle 468 

152. Paint Grinding Mill 469 

153. Hydrometer 486 

154. Westphal Balance 487 

155. Sommer Hydrometer 490 

156. Hubbard Pycnometer 490 

157. Weiss' Specific Gravity Pan 490 

158. Engler Viscosimeter 491 

159. Hutchinson's Tar Tester 492 

160. Hubbard's Consistency Tester 492 

161. Float Tester 493 

162. Schutte Viscosity Tester 494 

163. Needle Penetrometer 496 

164. Miniature Penetrometer 496 

165. Consistometer 499 

166. Dow Ductility Mould 502 

167. Smith Ductility Tester 503 

168. Author's Ductihty Mould 503 

169. Cross-Section Author's Mould 504 

170. Tensometer 505 

171. Osborne Adhesive Tester 507 

172. Kirschbraun Adhesive Tester 507 

173. Method of Filling K. and S. Fusing-point Tubes 5II 

174. Heating Coil for K. and S. Fusing-point Tester 5II 

175. K. and S. Fusing-point Tester 512 

176. K. and S. Tester for Hig'-> Fusing-point Substances 514 



ILLUSTRATIONS XXV 

PIQ. PAGE 

177. B. and R. Fusing-Point Tester , . 514 

178. Cube Fusing-Point Tester ^ . 515 

179. Cube Tester for High Fusing-Point Substances 515 

180. Shelf for VolatiUty Oven 517 

181. Volatihty Oven 518 

182. Pensky-Martens Closed Flash-Point Tester 518 

183. Cleveland Open Flash-Point Tester 519 

184. New York State Closed Flash-Point Tester 519 

185. Flask Method of Distillation 521 

186. Asbestos Shield for Retort 522 

187. Retort Method of Distillation 523 

188. Still for Determining Water 529 

189. Combustion Furnace for Ultimate Analysis 531 

190. Cary-Curr Extraction Apparatus 535 

191. Bureau of Standards' Modification of Le Chatelier's Specific Gravity Flask . . . 541 

192. Goldbeck's Specific Gravity Apparatus 542 

193. Mould for Ascertaining the Tensile Strength of Bituminized Aggregates 553 

194. Apparatus for Recording Distortion of Bituminized Aggregates under Heat . . 556 

195. Apparatus for Determining the Softening-Point of Bituminized Aggregates . . 557 

196. Forrest's Hot-Extraction Apparatus 558 

197. Centrifugal Extractor 558 

198. Mechanical Sifting Apparatus 559 

199. Types of Prepared Roofings 561 

200. Mandrels for Testing the Pliability of Prepared Roofings 561 

201. Tensile Strength Specimen 562 

202. Instrument for Testing the Tensile Strength of Prepared Roofings 562 

203. Method of Stripping the Coatings from the Saturated Felt 566 

204. Method of Removing the Coatings 566 

205. Exposure-Test Card 577 

206. Effects of Exposure on Smooth-Surfaced Prepared Roofings 579 

207. Enlargements of Specimens A and H in Fig. 206 580 

208. Tensile Strength Curves of Prepared Roofings on Exposure 581 



ASPHALTS AND ALLIED SUBSTANCES 



PART I 
GENERAL CONSIDERATIONS 



CHAPTER I 
HISTORICAL REVIEW 

Origin of the Words " Asphalt ** and " Bitumen. " The term '' as- 
phalt " may be traced back to Babylonian times. It was later adopted 
by the Homeric Greeks in the form of the adjective a(T<^a\ri^, U, signifying 
" firm," " stable/' '' secure," and the corresponding verb a(7<^aAt^o>, tW, 
meaning " to make firm or stable," '^ to secure." It is a significant fact 
that the first use of asphalt by the ancients was in the nature of a cement 
for securing or joining together various objects, and it thus seems likely 
that the name itself was expressive of this application. From the Greek, 
the word passed into late Latin, and thence into French (" asphalte ") 
and English ('' asphalt "). 

The expression '' bitumen " originated in the Sanskrit, where we find 
the word " jatu-krit," meaning '' pitch creating," '' pitch producing " 
(referring to coniferous or resinous trees) . The Latin equivalent is claimed 
by some to be '' gwitu-men " (pertaining to pitch), and by others, "pix- 
tumens " (exuding or bubbling pitch), which was subsequently shortened 
to " bitumen," thence passing via French into English. 

Use of Asphalt by the Sumerians (about 3000 to 2500 B.C.) The 
earliest recorded use of asphalt by the human race was by the pre-Baby- 
lonian inhabitants of the Euphrates Valley. These people, known as 
Sumerians, were skilled in carving and decorating stone, as evidenced by 
the varied and interesting specimens of pottery and statuary unearthed 



2 ASPHALTS AND ALLIED SUBSTANCES 

in recent years. In certain of these we find shells or bits of stone cemented 
in place by means of asphalt. 

In 1903-4, Dr. E. J. Banks, while excavating at Adab (known also as Bismya) 
between the Euphrates and Tigris Rivers in Syria, discovered a marble statue of 
Lugal-daudu, King of Adab (Fig, 1), one of the early Sumerian rulers, who lived 
about 3000 b.c.^ An inscription reveals the name of the city of Adab, The eye- 
sockets are hollow, and still show the presence of asphalt, indicating that they were 
once inlaid with some substance, probably ivory or mother-of-pearl. The statue 
is now on exhibition at the Ottoman Museum in Constantinople. ^ 




Fig. 2.- 



From "The Civilization of Babylonia and Assyria," J. B. Lippincott Co, 

-Human-Headed Bull (3000 b.c.) with Shells Inlaid in Asphalt. 



Another statute (Fig, 2) originating about the same time (3000 b,c,) known as 
the ''Human Headed Bull," is composed of black steatite, inlaid with small yellow 
shells imitating streaks, and held in place with asphalt. Many of the shells are intact, 
gripped firmly by the asphalt throughout fifty centuries of time and exposure, thus 
furnishing evidence of its remarkable adhesiveness and durability. This statue is 
now at the Louvre, Paris, ^ 

i"The Civilization of Babylonia and Assyria," by Morris Jastrow Jr., pp. 394-5, J. B, Lip- 
pincott Co, Phila., 1915. 

2 "Bismya," by E. J. Banks, p. 191. 

3 Fondation Eugene Piot, "Monuments et M^moires," by Ernest Leroux Paris Vol. VI, 
1899; also Vol. VII, 1900, 



HISTORICAL REVIEW 3 

An interesting specimen of Sumerian art was excavated at Lagash, near the mouth 
of the Euphrates, consisting of a sculptured votive offering dating back to Eutemena, 
ruler or so-called '' Patesi " of Shirpula (2850 b.c). This bears as an inscription, the 
heraldic device of Lagash, by means of which we are enabled to fix its date and origin. 
The tablet is an artificial composition of clay and asphalt (Fig. 3). It is also on 
exhibition at the Louvre.^ 

The bust of an early Sumerian ruler, Manishtusu, King of Kish (about 2600 b.c.) 
was found in the course of excavations at Susa, in Persia, whence it is supposed to 
have been carried by an Elamite conqueror in the twelfth century b.c.^ In describing 




Fig. 3. 



From "The Civilization of Babylonia and Assyria," J. B. Lippincott Co. 

-Heraldic Device of Lagash (2850 b.c.) Cast in Asphalt. 



this statue, M. de Morgan states: "the eyes, composed of white limestone, once 
ornamented with black pupils now fallen off, are held in their orbits with the aid of 
hitamen; the face appears rough; the beard and hair are of conventional design; 
as regards the inscription, it is engraved in lineal cuneiform characters of the most 
ancient style." (Fig. 4.) The original is at the Louvre. 

Another reHc, known as the "Libation Vase" (Fig. 5) is composed of green 
steatite, carved in the form of strange mythical monsters, the effect of which is 
heightened by incrusted little shells set in asphalt, to represent the scaly backs of 

1 Fondation Eugene Plot, " Monuments et M^moircs," by Ernest Leroux, Paris, Vol. I, 1894, 

2 " M^moires de la Delegation en Perse," published under the direction of M. de Morgan, Vol. II, 
1900, Plate IX; Vol, X, 1908, Plate I, published by Ernest Leroux, Paris; also Comptes Rendus 
de I'Academie d' Inscriptions, July 1907, pp, 398-9, Figs. 1 and 2, by M. de Morgan. 



4 ASPHALTS AND ALLIED SUBSTANCES 

winged serpents. The serpent was supposed to represent the emblem of the god 
Ningishzida, to whom the accompanying inscription shows the vase to be dedicated 
by Gudea, ruler or Patesi of Lagash (2500 B.C.). This is considered one of the 
best specimens of Sumerian sculpture, and represents the height of Sumerian art. 
It is also at the Louvre.^ 




From "The Civilization of Babylonia and Assyria," J. B. Lippincott Co. 

Fig. 4. — Bust of Manishtusu, King of Kish (2600 b.c.) with Eyes Set in Asphalt. 

Use of Asphalt by the Early Persians (about 2800 to 2500 B.C.). A 

number of specimens of Persian sculpture involving the use of asphalt 
were exacvated at Susa in the province of Susiana, Persia, by M. J. de 
Morgan's expedition of Paris. ^ These are in an excellent state of preser- 

* " D6couvertes en Chald6e"; also "Catalogue des Antiquit^s Chald^ennea du Mus6e Na- 
tional du Louvre," by Henzey, Paris, 1902, No. 125. 

2"M6moires — D616gation en Perse," published under the direction of J. de Morgan, Vol. 
XIII, "R6cherchea Arch6ologiques Cinquifime S^rie de I'Epoque Archalque," by Edm. Pottier, 
published by Ernest Leroux. Paris, 1912. 



HISTORICAL REVIEW 



5 



vation, and by the inscriptions and characteristic ornamentation are sup- 
posed to have originated between 2800 and 2500 B.C. 

Fig. 6 shows various small animals carved of alabaster having the eyes cemented 
in place with asphalt; Fig. 7, two decorated vases 
composed wholly of asphalt; and Fig. 8, a sculp- 
ture of an animal in primitive form, hewn from 
a mass of asphalt. The French chemist, Henry 
Le Chatelier, analyzed some of the asphalt, and 
found it to consist of the following: ^ 

Moisture, 2.8 per cent; asphalt, 24.4 per cent; wax, 
1.6 per cent; mineral matter, 71.2 per cent. The mineral 
matter was composed of: calcium carbonate, 45.2 per cent; 
calcium sulphate, 3.5 per cent; calcium phosphate, 0.8 per 
cent; iron, aluminium and silicon oxides, 21.7 per cent. 

This is conclusive proof that the asphalt is a 
natural product composed of 25 per cent asphalt 
and 75 per cent mineral matter, similar to the 
material obtained in the locality at the present 
day. (See p. 126.) 




From "The Civilization of Babylonia 
and Assyria," J. B. Lippincott Co. 

Fig. 5. — ^Libation Vase Dedicated 
to Gudea, Ruler of Lagash 
(2500 B.C.), Showing Shells Set 
in Asphalt. 



Use of Asphalt by the Early Egyptians 
(about 2500 B.C.). The ancient Egyptians 
used asphalt for preserving their dead rulers, by wrapping the bodies 
in cloth and coating them with liquid or melted asphalt. The remains 
are known as " mummies," and at one period this word was syn- 





'^^^i 




From "M6moires de la D6l6gation en Perse," by Edm. Pottier. 

Fig. 6. — ^Early Persian Sculpture with Eyes Set in Asphalt. 



onymous with " asphalt." The oldest mummies in existence concern- 
ing which we have authentic data, date back to the Sixth Egyptian 
Dynasty (about 2500 B.C.). The oldest specimens include the mummy of 
Seker-em-sa-f, unearthed at Sakkarah in 1881, and exhibited at Giza, 
near Cairo,^ and the mummy of King Merenre, now at the Boulak Museum, 
Cairo.3 

»"M6moire9," Vol. XIII, p. 162. 

2 "The Mummy," by E. A. Wallis Budge, pp. 184, Cambridge University Press, 1893. 

3 "Natural Rock Asphalts and Bitumens," by Arthur Danby, pp. 41, New York, 1913. 



6 



ASPHALTS AND ALLIED SUBSTANCES 



Use of Asphalt in Biblical Times (2500 to 1500 B.C.). Some contend 
that Noah used asphalt in the construction of the Ark (Genesis -VI, 14). 

The Biblical text reads, that it was 
treated with '' pitch " within and 
without: '' bituminabis eam bitumi- 
nae " (Vulgate). There is some 
doubt as to whether this referred to 
asphalt, as pine pitch was known 
at the time, and might very well 
have been used for this purpose. If 
asphalt was actually used, the date 
would be fixed at approximately 2500 
B.C., which is usually assigned to the 
Deluge. 




From "M6moires de la D616gation 
en Perse," by Edm. Pettier. 

Fig. 7. — Persian Vases Hewn from 
Blocks of Asphalt. 



We find numerous other references in 
the scriptures to substances corresponding 
to what we now know to be asphalt. The Book of Genesis (XI, 3) in describing 
the building of the Tower of Babel (about 2000 B.C.) states. . . . "and they had 
brick for stone, and slime had they for mortar." There seems to be no question 
but that the so-called "shme" alludes to asphalt, since the word translated as "slime" 
in the EngUsh version, occurs as d«r0aXros in the Septuagint, and as "bitumen" in 
the Vulgate. In Genesis (XIV, 10) we are informed that the Vale of Siddim "was 




From "M6moires de la D6I6gation en Perse," by Edm, Pottier. 

Fig. 8. — Primitive Animal Carved from Asphalt. 



full of slimepits" referring' no doubt to exudations of liquid asphalt. Moreover, it 
is pointed out by certain authorities that the area described as the Vale of Siddim 
corresponds to our present Dead Sea, from which asphalt is still obtained. (See 
p. 135.) 

Again we are told (Exodus II, 3) that in constructing the basket of bulrushes 
in which Moses was placed, it was daubed "with slime and with pitch." This took 
place about 1500 B.C. (" Septuaginta Interpretes," Tischendorf). 

Use of Asphalt by the Babylonians (700 to 500 B.C.). The Babylonians 
were well versed in the art of building, and each monarch commemorated 



HISTORICAL REVIEW 7 

his reign and perpetuated his name by constructing some vast engineering 
work. Certain kings built roadways, others built retaining walls to 
impound the waters of the Euphrates, and still others mighty battlements 
and palaces. The facts were indelibly recorded by inscriptions on the 
bricks used for the purpose, many of which are still in existence. 

The following inscription occurring on the bricks of the so-called "Sargeon Wall" 
of Babylon, built by King Sargeon who ruled 710 to 705 b.c, has been translated 
by Delitzsch: ^ 

" To Marduk, the Great Lord, the divine Creator, who inhabits Esagila, the 
Lord of Babil, his lord Sargeon, the mighty king, King of the land of Assur, 
King of all, governor of Babil, King of Sumer and Akkad, the nourisher of Esagila 
and Ezida. To build Imurg-Bel was his desire; he caused burnt brick of pure 
Kiru (?) to be struck, built a kar (?) with tar and asphalt on the side of the Ishtar 
Gate to the bank of the Euphrates in the depth of the water, and founded 
Imgur-Bel and Nimitti-Bel mountain high, firm upon it. This work may Marduk, 
the great Lord, graciously behold, and grant Sargeon, the prince who cherishes him, 
life! Like the foundation stone of the Sacred City, may the years of his reign 
endure." 

This revealed the use of asphalt as a cement for joining together bricks. Modern 
excavations indicate that this method was used quite generally, as will be described 
in greater- detail later. "Imgur-Bel" was the name given to the inner wall of 
Babylon, and "Nimitti-Bel" to the outer. 

Of all the Babylonian rulers, Nebuchadnezzar, who reigned 604 to 561 B.C., was 
the most progressive, and is stated to have reconstructed the entire city. The 
bricks bore inscriptions relating to his work, and several refer specifically to the 
use of asphalt. One found in the so-called "Procession Street" which led from 
his palace to the North wall, reads as follows (Translation by Weissbach, Kolde- 
wey, p. 54): 

" Nebuchadnezzar, King of Babylon, he who made Esaglia and Ezida glorious, 
son of Nabopolassar, King of Babylon. The streets of Babylon, the Procession 
Street of Nabti and Marduk, my lords, which Nabopolassar, King of Babylon, the 
father who begot me, had made a road glistening with asphalt and burnt bricks; 
I, the wise suppliant who fears their lordships, placed above the bitumen and burnt 
bricks, a mighty superstructure of shining dust, made them strong within with 
bitumen and burnt bricks as a high-lying road. Nabti and Marduk, when you 
traverse these streets in joy, may benefits for me rest upon your lips; life for distant 
days, and well-being for the body. Before you I will advance upon them. May 
I attain eternal age!" 

This would seem to be the forerunner of the present-day pavement composed 
of stone blocks set in asphalt. It seems strange that the art should have become 
lost to mankind, only to be rediscovered in the nineteenth century a.d. According 
to Nebuchadnezzar, his father, Nabopolassar (625-604 B.C.) is credited to have laid 
the first asphalt block pavement of which we have any record. 

The most comprehensive relic left by Nebuchadnezzar is known as the "Large 
Inscribed Stone Tablet" (sometimes referred to as the "East India House Inscrip- 

1 "The Excavations at Babylon," by Robert Koldewey, pp. 138, Macmillan & Co., Ltd., London, 
1914. 



8 ASPHALTS AND ALLIED SUBSTANCES 

tion"), which contains a detailed account of his building activities. A translation 
by Delitzsch reads in part as follows (Column 7, lines 34 et seq.): 

" In Babil, my favorite city that I love, was the palace, the house, the marvel 
of mankind, the center of the land, the dwelling of majesty, upon the Babil place 
in Babil, from Imgur-Bel to the eastern canal Libil-Higalla; from the bank of the 
Euphrates to Aibursabu, which Nabopolassar, King of Babylon, my father, my 
begetter, built of crude bricks, and dwelt in it. In consequence of high waters, 
its foundations had become weak, and owing to the filling up of the streets of 
Babil, the gateway of that palace had become too low. I tore down its walls 
of dried brick, and laid its corner-stone bare, and reached the depth of the waters. 
Facing the water, I laid its foundation firmly, and raised it mountain high with 
bitumen and burnt brick. Mighty cedars, I caused to be laid down at length for its 
roofing. . . . For protection, I built two massive walls of asphalt and brick, 
490 ells beyond Nimitti-Bel. Between them I erected a structure of bricks on 
which I built my kingly dwelling of asphalt and bricks. This I surrounded with a 
massive wall of asphalt and burnt bricks, and made upon it a lofty foundation for 
my royal dwelling of asphalt and burnt bricks." 

It thus appears that Nebuchadnezzar profited by the experience of his father, 
and instead of building a retaining wall of dried clay bricks which had failed to 
hold back the Euphrates, due to its lack of waterproof properties, he resorted to 
the use of burnt bricks and asphalt, as originally practiced by Sargeon, and appa- 
rently with satisfactory results. 

Koldewey's investigations (p. 31) indicate that the method of constructing walls 
in Babylonian times consisted in laying in rotation, first a course of bricks, then 
a layer of asphalt, then a layer of clay and then another course of bricks. The 
joints in each course were composed of asphalt and clay. In every fifth course, 
the clay was replaced by a matting of reeds. This matting is now entirely rotted 
and gone, but its impression is clearly recognizable in the asphalt. An attempt to 
separate the courses to prevent adhesion is thus apparent, but the reason is not 
obvious. Only in one locality (Temple of Borsippa) does it appear that asphalt has 
been used in direct contact with the bricks, where they still hold together in a 
firm mass. 

It is probable that the asphalt used by the Babylonians was dervied from springs 
similar to the ones still found in Mesopotamia, of which Fig. 9 is a typical example. 

Fig. 10 shows the present appearance of the brick floor of Nebuchadnezzar's 
Throne Hall, Babylon, looking towards the Euphrates. The burnt bricks bearing 
the name of Nebuchadnezzar (of which one is shown in the foreground) were laid 
in asphalt, and are still so firmly jointed together to-day, that it is impossible to 
part them without destroying their integrity. ^ 

About 450 B.C. — Herodotus of Persia. The Persian Herodotus in 
his "Historiarum/'^ published about 450 B.C., refers to several sources of 
Persian asphalt. In describing the springs of the Island of Zante, he 
writes: '' I have myself seen the pitch drawn up out of a lake, and from 
water in Zacynthus; and there are several lakes there; the largest of them 
was 70 ft. every way and 2 orgyoe in depth; into this they let down a 

1 National Geographic Magazine, Feb., 1916. 29, pp. 130 and 151. 
'Volume I, pp. 119 and 179; also Volume IV, p. 195. 



HISTORICAL REVIEW 



9 



pole with a myrtle branch fastened to the end, and then drew up the pitch 
adhering to the myrtle; it has the smell of asphalt; but is in other respects 
better than the pitch of Pieria." Herodotus also mentions the fact that 
lumps of asphalt are carried down by the waters of the Is, which discharges 
into the Euphrates at the City of Is, about eight days' journey from Baby- 
lon. It is probable that the City of Is referred to by Herodotus corre- 




FiG. 9. 



From "Light on the Old Testament," by Prof. A. T. Clay. 
-Asphalt Spring in Mesopotamia. 



sponds to the present city of Hit, where bitumen is still found in con- 
siderable quantities. (See p. 126.) 

Herodotus also states: "At Ardericca near Susa is a well which produces three 
different substances, since asphalt, salt and oil are drawn up from it. . . . It as- 
sumes these different forms: the asphalt and the salt immediately become soHd, 
but the oil they collect and the Persians call it Rhadinance ; it is black and 
emits a strong odor." At Elam in the province of Susiana in Persia, asphalt is 
still collected in this crude manner. Herodotus was the first to describe petroleum, 
of which he states an occurrence existed at Kirab, Persia. 

About 430 B.C. — Xenophon of Greece. The Greek Xenophon (about 
4:30 B.C.) in his work ''Anabasis " ^ describes a wall built in Media com- 
posed of burnt bricks laid together in hot asphalt as the cementing medium. 
This apparently is similar to the method of construction used at Babylon. 

1 Book II, Chapter IV, Section 12. 



10 



ASPHALTS AND ALLIED SUBSTANCES 



About 400 B.C. — Hippocrates of Greece. The Greek philosopher and 
physician Hippocrates, in his treatise " On Airs, Waters and Places/^ 
refers to several of the asphalt deposits already mentioned. 

About 350 B.C.— Aristotle of Greece. Aristotle refers to " Asphalt '' 
in his works 1 and describes the well-known Albanian deposits still found 
on the eastern shore of the Adriatic Sea (see p. 90). 




Copyright by Underwood & Underwood, N. Y. 

Fig. 10. — ^Floor of Nebuchadnezzar's Temple as it Appears To-day, Showing Blocks 

Joined by Means of Asphalt. 



About 250 B.C.— Hannibal of Carthage. Hannibal, who lived in 
Carthage about 250 B.C., is given the credit of having used asphalt, and 
possibly also mineral oils in compounding the so-called " Greek Fire " 
{" Ignse Vestce "). This was used in warfare, and was claimed to burn so 
fiercely that even water would not extinguish it. 

1 " De Mirabilibus Auscultationibus," Chapter CXXVII. Edition of F. Didot, 1857. 



HISTORICAL REVIEW 11 

About 80 B.C. — Diodorus Siculus of Sicily. The historian Diodorus 
Siculus of Sicily/ upon referring to a pecuHar manifestation which occurred 
in the Dead Sea, informs us that large masses of asphalt became detached 
from the bottom, and on account of the unusual amount of salt in the 
water, floated to the surface, forming small islands. Diodorus states fur- 
ther that before the appearance of the asphalt, a very strong odor was 
noticeable which darkened copper, silver and other metals. This was 
undoubtedly the result of volcanic action or earthquake shock. He also 
refers to the fact that in constructing the walls of the City of Media, the 
stones were cemented together with asphalt, as previously noted by 
Xenophon. Diodorus states that the natives gather asphalt from the 
Dead Sea and carry it to Egypt where they sell it to those who make a 
profession of embalming bodies, because " without the mixture of this 
material with other aromatics, it would be difficult for them to preserve 
these for a long time from the corruption to which they are liable." 

About 30 B.C. — Strabo of Greece. Strabo, who also lived about this 
time (30 B.C.), in his book the " Geographica "^ refers to the same mani- 
festation, in which the surface of the Dead Sea suddenly became very much 
disturbed and large masses of asphalt floated to the surface. Strabo 
Teports that the asphalt which rose to the surface first appeared in a 
molten condition but soon solidified. He also mentions an occurrence 
of asphalt in Babylon, close to the River Euphrates, probably the same 
as previously described by others. 

About 25 B.C. — Marcus Vitruvius of Rome. The architect, Marcus 
Vitruvius, who lived about the time of Christ, also reported the presence 
of asphalt in the neighborhood of Babylon, which he describes as being of 
a liquid consistency.^ 

We have similar accounts from other writers who lived in the first 
century, including the Greek Plutarch,^ Flavins Josephus the Roman,^ 
Tacitus of Rome,^ and others. 

About 60 A.D. — Dioscorides of Greece. In his book entitled " Materia 
Medica " we find an accurate description of the occurrence of asphalt in 
the Dead Sea, referred to by him as Lake AsphaltitesJ He also describes 
a compound of pitch and asphalt termed ''pissasphaltum"^ He adds that: 

1 " Bibliotheca," Book XVI, Chapter 40; Book I, t. II, Chapter XXIX. Also "Hist. Universe," 
Book VI, t. XIX, Chapter XXV. 

2 Volume XVI, Chapters I, II, and XII; Volume I, Chapter XVI; French translation by 
Casat, XIV, p. 665. 

3 " De Architectura," Volume VII, Chapter III. 
« "Life of Sylla." 

5 "Antiquities," Book I, Chapter IV. 

«"The Histories," Volume V, p. 6. 

' "Materia Medica," I, 109; V, 145; XIX, 98; Kuhn Lipsiae, 1829; Saracen, 1598. 

8 "Materia Medica," I, 100. 



12 ASPHALTS AND ALLIED SUBSTANCES 

"the name Milmia is given to the drug called 'Bitumen of Judea,' and to the 
Mtimia of the tombs found in great quantities in Egypt, and which is nothing more 
than a mixture which the Byzantine Greeks used formerly for embalming their 
dead, in order that the bodies might remain in the state in which they were buried, 
and experience neither decay nor change. Bitumen of Judea is the substance which 
is obtained from the Asphaltite Lake. ..." 

About 100 A.D.— Pliny the Elder of Rome. Pliny the Elder of Rome, in 
his treatise "Naturalis Historia" written about the year 100 a.d./ makes 
the interesting observation that " Real asphalt must be glossy and black, 
otherwise it is adulterated with pitch." He thus appears to have under- 
stood the difference between asphalt which occurred naturally, and adulter- 
ated mixtures containing pine pitch. He notes ^ that the Romans were in 
the habit of coating their images with asphalt to protect them from the 
weather. This corresponds to the present day use of asphalt paints for sim- 
ilar purposes. Pliny describes the use of asphalt for medicinal purposes 
and recommends it for curing boils, inflammation of the eyes, coughs, 
asthma, blindness, epilepsy, etc. It was sold extensively under the name 
'' Mummy," and we are informed that the asphalt so used was actually 
scraped from the mummies taken from tombs. Its alleged curative proper- 
ties were explained by the fact that it preserved the dead for so many 
centuries. 

About 1300 A.D. — ^Marco Polo of Venice. Marco Polo at the end of 
the thirteenth century described seepages of liquid asphalt at Baku on 
the Caspian Sea.^ He also mentioned the existence of an ancient fire 
temple erected about flaming streams of gas and oil, which we are informed 
constituted a place of Hindoo pilgrimage. 

1535. Discovery of Asphalt in Cuba. In the " General History of the 
Antilles " by G. F. Oviedo y Valdes of Spain, published in 1535, we find a 
description of a spring of semi-liquid asphalt in the Province Puerto Prin- 
cipe, near the coast, which was used for painting the hulls of ships. An- 
other occurrence is mentioned on the shore of Havana harbor, used for 
similar purposes (p. 107). 

1595. Discovery of '* Pitch Lake " at Trinidad by Sir Walter Raleigh. 
In his book, the " Discoveries of Guiana," Sir Walter Raleigh gives a 
record of his voyage of exploration to the east coast of South America 
in 1595, wherein he describes his visit to the Island of Trinidad, and gives 
the first account of the so-called " Pitch Lake," (see p. 108). 

1601. First Classification of Bituminous Substances. Andreas Libavius 
refers to the uses of asphalt, and classified it with mineral oil, amber and 
pitch. He endeavored to trace the connection between asphalt and 

1 Volume II. * Book XXXV. « Book I, Chapter III. 



HISTORICAL REVIEW 13 

petroleum, and gives a record of the earliest literature on asphalt including 
the works of Pliny, Dioscorides, Hippocrates and others.^ 

1656. Early Dictionary Definition of "Bitumen." In one of the earliest 
dictionaries of the English language, " Blount's Glossary," bitumen is 
defined as: 

"A kind of clay or slime naturally clammy, like pitch, growing in certain countries 
of Asia." 

It is interesting to note the connection between this interpretation of the 
word, and the reference to '' slime " and " slimepit " in " Genesis " 
(loc. cit.). 

1661. Commercial Production of Wood Tar. The earhest reference to 
the production of wood tar on a large scale by the dry distillation of wood, 
occurs in Boyle's " Chemistra Scepticus," 1661. This industry is said to 
have been first practiced in Norway and Sweden. 

1672. First Accurate Description of Persian Asphalt Deposits. Dr. J. 
Fryer accurately describes the occurrences of asphalt in the East Indies 
and Persia, in his book ''Nine Years' Travels " (1672-1681).2 

1673. Discovery of Elaterite. The first description of Elaterite, origi- 
nally found at Castleton in Derbyshire, England (p. 150), under the 
name " Elastic Bitumen," is given by Lister in the Philosophical Magazine 
and Journal of Science, London, 1673. 

1681. Discovery of Coal Tar and Coal-tar Pitch. In a patent taken out 
in England on August 19, 1681, by Becher and Serle, entitled ''A new way 
of Makeing Pitch, and Tarre out of Pit Coale, never before found out or 
used by any other," we find the first description of coal tar and coal-tar 
pitch, as well as their methods of production. 

1691. Discovery of Illuminating Gas from Coal. Dr. John Clayton, 
dean of Kildare, England, experimented with the inflammable gas ob- 
tained on heating coal in a closed retort. He filled bladders with this gas 
and demonstrated that it burnt with a luminous flame. 

1694. Discovery of Shale Tar and Shale-tar Pitch. English Patent 
No. 330, of 1694, entitled " Pitch, Tar and Oyle, out of a kind of stone from 
Shropshire," granted to Hancock and Portlock, contains the earliest record 
of the manufacture of shale tar and shale-tar pitch. 

1712-1730. Discovery of Val de Travers, Limmer and Seyssel Asphalt 
Deposits. The asphalt deposit in the Val de Travers in the Jura Moun- 

* " Singularium Andrese Libavii, cont VIII libros bituminum et aflSnum historice, physice, 
chymice; de Petroleis, Ambra, Halosantho, Succino, Gagate, Asphalto, Piss-asphalto, Mumia, 
Lithanthrace." Frankfurt, 1601. P. Kopff. 

2 P. 318 et seq. 



14 ASPHALTS AND ALLIED SUBSTANCES 

tains, Canton of Neuchatel, Switzerland, was discovered by the Greek 
Doctor Eyrinis d'Eyrinis in 1712, and described in detail. ^ 

Some give Eyrinis the credit of having likewise discovered the Limmer 
asphalt deposit near Hanover, Germany, in 1730, but this has not been 
definitely established. A third discovery of asphalt by Eyrinis, in 1735, 
at Seyssel in the Rhone Valley, Department of Ain, France, proved to be 
one of the most important deposits in Europe. This has been worked 
constantly up to the present time, and will be described later (p. 116). 

1746. Invention of the Process of Refining Coal Tar. On August 7, 
1746, a patent was granted in England to Henry Haskins disclosing: " A 
new method for extracting a spirit or oil from tar, and from the same 
process obtaining a very good pitch," consisting of our present process of 
fractional distillation in a closed retort connected with a worm con- 
denser. 

1777. First Exposition of Modern Theory of the Origin of Asphalt. In 
his ''Elements de Mineralogie," published in 1777 LeSage^ classified bitu- 
mens in the sequence: '' Naphtha, Petroleum, Mineral Pitch, Maltha and 
Asphalt," and regarded them all as originating from petroleum oil. This 
closely conforms to the modern views regarding the classification and origin 
of bitumens. (See p. 55.) 

1788. Discovery of Lignite Tar. Kriinitz in 1788 referred to the pro- 
duction of '' a tar-like oil " upon destructively distillating " earth coal " 
(lignite). This was virtually the first description of the manufacture of 
lignite tar. 

1790-1800. Discovery of " Composition " or " Prepared " Roofing. 
Admiral Faxa of Sweden^ is given credit for having produced the first 
prepared roofings between the years 1790 and 1800 in the following crude 
manner: the roof boards were first covered with plain paper, which, 
after being nailed in place, was coated with heated wood tar to make it 
waterproof. 

A newspaper published in Leipsic in the year 1791 credits Michael Kag of 
Miihldorf, Bavaria, with having produced an improved form of prepared roofing by- 
saturating raw paper with varnish, and coating the surfaces with a mineral powder. 
The product was also recommended as a substitute for leather in the soles of shoes. 

1792-1802. Manufacture of Coal Gas and Coal Tar on a Large Scale. 

Wm. Murdoch, of England, was the first to manufacture coal gas and 
coal tar on a large scale. 

1 " Dissertation sur I'asphalte ou ciment naturel, decouvert depuis quelques ann^es au Val de 
Travers." Paris, 1721. 

2 Volume II, p. 96. 

' E. Liihmann, "Die Fabrikation der Dachpappe und der Anstrichmasse fur Pappdacher," p. 1, 
Vienna, Budapest and Leipzig, 1883. 



HISTORICAL REVIEW 15 

1797-1802. Exploitation of Seyssel Asphalt in France. M. Secretan 
obtained a concession from the French Government to work the asphalt 
deposits at Seyssel on the Rhone, France. The venture, however, did 
not prove a success. The deposit was next taken over by Count de 
Sassenay, of France, in 1802, and actively exploited. A laboratory was 
erected to investigate the uses of this asphalt, which was marketed in 
France under the name " Eock asphalt mastic," and used for surfacing 
floors, bridges and sidewalks, also to a limited extent for waterproofing 
work (see p. 374). 

1815. Commercial Exploitation of Coal-tar Solvents. In 1815, 
F. C. Accum, of England, obtained " naphtha " by subjecting coal 
tar to fractional distillation on a commercial scale. This distillate was 
used in the manufacture of India rubber goods, for burning in open lamps 
and for certain kinds of varnish. The tar which remained behind had no 
particular value and was accordingly consumed as fuel. 

1822. Discovery of Scheereiite and Hatchettite. The mineral wax 
Scheererite was discovered in a bed of lignite (brown coal) at Uznach, 
near St. Gallen in Switzerland, by Captain Scheerer, in 1823. In the same 
year the mineral wax hatchettite or hatchetine (p. 78) was dis- 
covered on the borders of Loch Fyne, in Argyllshire, Scotland, and was 
named after the English chemist, C. Hatchett. 

1830. Discovery of Paraffin Wax. The discovery of paraffin wax is 
credited to Carl von Reichenbach, of Stuttgart, Germany, who was the 
first to describe its physical and chemical properties. ^ He derived the 
material from lignite tar and christened it '^ Paraffin " (Parum Affinis), 
because of its unusual resistance to chemicals. 

1833. Discovery of Ozokerite. The first reference to the mineral wax 
ozokerite (p. 74) was by Glocker^ in Schweitzerische Apotheker-Zeitung, 
1833, 69, 215. He discovered it near the town of Slanik in Moldavia, close 
to a deposit of lignite at the foot of the Carpathians. It was named from 
the Greek words signifying '' to smell " and " wax," in allusion to its odor. 

1836. Asphalt First Used in London for Foot Pavements. In 1836 
we first hear of Seyssel asphalt being introduced from France to London 
for constructing foot paths. ^ 

1837. Publication of First Exhaustive Treatise on the Chemistry of 
Asphalt. The well-known treatise " Memoir sur la composition des 
bitumes " was published by J. B. Boussingault in the year 1837. It 
was the most exhaustive treatise on the subject which had yet appeared.^ 

»J. Chim. phys., 1830, 69, 436. 

'"A System of Mineralogy," by E. S. Dana, p. 998, New York, 1906. 
' Danby, loc. cit., p. 54. 

^ Ann. chim. phys., 1837, 64, 141. Translated in "Asphalt Paving," pp. 107, by the Com- 
missioners of Accounts of the City of New York, Feb. 3, 1904. 



16 ASPHALTS AND ALLIED SUBSTANCES 

1838. Discovery of Process for Preserving Wood with Coal-tar Creosote. 

In 1838 Bethell disclosed the use of coal-tar oil for impregnating wood.^ 
1838. Asphalt First Used in the United States for Foot Pavements. 
The earliest case on record of rock asphalt being used in the United States 
for sidewalks is in the portico of the old Merchants' Exchange Building, 
Philadelphia, in 1838. Seyssel asphalt was used for this purpose. 

1842. Discovery of Bituminous Matter in the United States. In 
1842 appeared the first report of an asphalt deposit in the United States. 
It was entitled " Indurated Bitumen in Cavities of the Trap of the Con- 
necticut Valley." ^ 

1843. Bituminous Matters Discovered in New York State. L. C. 
Beck, in 1843, wrote a paper on the occurrence of bituminous matter in 
several of the New York limestones and sandstones. ^ 

1850. Discovery of " Asphaltic Coal " in New Brunswick, Nova 
Scotia. C. T. Jackson published the first account of Nova Scotia " alber- 
tite " in the years 1850-1851. It was described as '' Albert Coal."^ 

1854. First Compressed Asphalt Roadway Laid in Paris. In 1854 a 
short stretch of compressed rock asphalt roadway was laid in Paris by 
M. Vaudry.^ This, we are told, was the outcome of observations previously 
made by a Swiss engineer, M. Merian who in 1849, noted that fragments 
of rock asphalt that fell from the carts transporting the material from the 
mine at Val de Travers, to the nearby village, became compressed in 
summer under the wheels into a crude pavement of asphalt. Merian 
thereupon constructed a small experimental stretch of roadway com- 
pacted with a roller. 

1858. First Modem Asphalt Pavement Laid in Paris. In 1858, the 
first large area of asphalt roadway was constructed on the Palais Royal in 
Paris. It was composed of a foundation of concrete 6 in. thick surfaced 
with rock asphalt mastic obtained from the Val de Travers deposit, com- 
pressed to a layer about 2 in. thick. This constituted the earliest use of 
sheet asphalt pavement in its modern form. 

1863. Discovery of Grahamite in West Virginia. The first account 
of the West Virginia grahamite deposit is given by J. P. Lesley.^ The 
material was described as a rock asphalt, but was later named ''gra- 
hamite " by Henry Wurtz, in honor of the Messrs. Graham, who were 
largely interested in the mine. 

i"Die Chemie und Technologie der Natiirlichen und Kiinstlichen Asphalte," by Kohler-Graefe, 
pp. 21. Braunschweig, 1913. 

2 J. G. Percival, "Report on the Geology of Connecticut," Am. J. Set., 1842, 13, 130. 

3 Am. J. Sci., 1843, 14, 335. 

iProc. Boston Soc. Nat. Hist., 1850, pp. 279, also Am. J. Sci., 1850, 2, XI, 292; XIII, 276. 
BSee "Asphalts," by T. H. Boorman, pp. 11, N. Y., 1908. 
e Proc. Am. Phil. Soc, 9, 183. Philadelphia, March 20, 1863. 



HISTORICAL REVIEW 17 

1869. The First Compressed Asphalt Pavement in London. The 

first stretch of asphalt roadway in London was laid at Threadneedle Street 
near Finch Lane in May, 1869. It was composed of Val de Travers 
rock asphalt.^ 

1870-6. First Asphalt Roadways in the United States. Some give 
the Belgium chemist, E. J. De Smedt, credit for having laid the first rock 
asphalt roadway in the United States, contending that in 1870 a small 
experimental stretch was laid with continental asphalt opposite the 
City Hall in Newark, N. J. According to Boorman,^ the first pavement of 
any consequence in the United States was laid in 1872, at Union Square, 
New York City, composed of Val de Travers rock asphalt. In 1876, four 
city blocks of Neuchatel asphalt pavement were laid on Pennsylvania 
Avenue, Washington, D. C. 

1879. First Trinidad Asphalt Pavement Laid in the United States. Ac- 
cording to Richardson ^ the first sheet asphalt pavement of Trinidad asphalt 
to be laid in the United States was on Vermont Avenue, Washington, D.C., 
in the year 1879. 

1881. Use of Chemicals for Oxidizing Coal Tars and Petroleum 
Asphalts. The first complete disclosure of the process for " oxidizing " 
bituminous materials was by De Smedt (see p. 287). This process 
consisted in evaporating coal tar or asphalt in contact with substances 
capable of inducing oxidation (such as potassium permanganate), " to 
give them greater tenacity and render them, or the pavement, or other 
compositions in which they enter, less brittle and less liable to be affected 
by air or water." (See p. 289.) 

1885. Discovery of Uintaite (Gilsonite) in Utah. Gilsonite, first known 
as " uintaite," was discovered in the Uinta Valley near Fort Duchesne, 
Utah, in 1885. It was first described by W. P. Blake,^ and was later 
called ^'gilsonite," after Mr. F. H. Gilson, of Salt Lake City. 

1889. Discovery of Wurtzilite in Utah. W. P. Blake subsequently 
discovered a deposit of wurtzilite not far from the source of gilsonite in 
the Uinta Valley, Wasatch County, Utah, between Salt Lake and the 
Valley of the Green River. ^ It was named after Dr. Henry, Wurtz of 
New York. 

1891. Exploitation of the Bermudez Asphalt Deposit, Venezuela. 
According to Kohler-Graefe,^ the Bermudez asphalt deposit in Venezuela 
was first developed in the year 1891 by the Barber Asphalt Paving Co. A 

1 Danby, loc. cit., pp. 60. 

2 Loc. cit., p. 11. 

3 "Trinidad and Bermudez Lake Asphalts," pp. 28. Barber Asphalt Paving Co. Philadelphia. 
^Eng. Mining J., 40, 431. 1885. 

^ Eng. Mining J., 48, 542, 1889. 
6 Loc. cit., pp. 34-35. 



18 ASPHALTS AND ALLIED SUBSTANCES 

search of the hterature fails to reveal when this deposit was first discovered. 
The first pavement laid with this material was on Woodward Avenue, 
Detroit, Mich., in 1892. 

1894. Use of Air for Oxidizing Petroleum Asphalt. A further devel- 
opment of the De Smedt process for oxidizing petroleum asphalt was 
brought about by F. X. Byerley, of Cleveland, O., who blew air through 
asphaltic oils maintained at a temperature of 600° F. The resulting 
product, marketed under the name of " byerlyte," attained great pop- 
ularity. (See p. 287.) 



CHAPTER II 

TERMINOLOGY AND CLASSIFICATION OF BITUMINOUS 

SUBSTANCES 

One of the most baffling problems with which we have had to deal in 
recent years is fixing the definitions of the various bituminous substances, 
and the products in which they are used in the arts.^ 

The words " bitumen," " asphalt," " resin," " tar," " pitch," " wax," 
have been in use for many centuries, most of them long before the advent 
of the English language. At first, very little was known regarding the 
properties of these substanes, and, as a result, the early writers used these 
terms loosely, and, in many cases, interchangeably. It is probable that 
each of these words at first related to the aggregate characteristics of some 
typical substance closely associated with the processes of daily life. As 
nothing of the chemistry was know^n when these terms originated, they 
were at first differentiated solely by their physical characteristics. 

The words originally had but a limited meaning, but as new sub- 
stances were discovered, they were extended in scope until the various 
expressions completely outgrew their former bounds. This resulted in 
a certain amount of overlapping and ambiguity. 

As the chemistry of these substances gradually became known, this 
means was likewise adopted to differentiate between them, but we are still 
compelled to rely principally upon the physical characteristics, in arriving 
at a rational basis of terminology, as their chemistry has been unrav- 
elled to but a limited extent. 

In defining a substance, we must rely on one or more of the foUowdng 
criteria : 

Origin, Solubility, 

Physical Properties, Chemical Composition. 

^ Unfortunately, at the present time there . is no uniform or standard system of nomenclature, 
and no two authorities agree on this subject: sre "Natural Asphaltum and its Compounds," J. W. How- 
ard, Troy, N. Y., 1894; "Asphalt, Its Occurrence, Composition, Adulterations, and Commercial 
Uses, with Schemes for its Analysis," T. B. Stillman, Stevens Institute Indicator, 21, 389, 1904; 
22, 45, 1905; Am. Soc. Testing Materials, Standards for, 1916; pp. 594, Proc. Am. Soc. Testing 
Materials, 16, Part I, 594, 1916; U. S. Department of Agriculture, Office of Public Roads, Cir- 
cular No. 93, 1911; The Engineering Standards Committee's Report on "British Standard Nomen- 
clature of Tars, Pitches, Bitumens, and Asphalts, when used for Road Purposes," London, April, 
1916; "The Modern Asphalt Pavement," by Clifford Richardson, pp. Ill, New York, 1908; "The 
Classification of Bituminous and Resinous Substances," by Herbert Abraham, /. Ind. Eng. Chem., 
5, 11, 1913. 

19 



20 



ASPHALTS AND ALLIED SUBSTANCES 



The last three can be more or less readily ascertained from an 
examination of the substance itself. The origin, however, is not always 
apparent, but may in certain cases be deduced by inference, upon in- 
vestigating the physical properties, solubility and composition of the 
substance under consideration. To base a definition solely upon a state- 
ment of the origin of a substance would necessitate some prior knowledge 
concerning its source or mode of production. As such knowledge is not 
always available, a definition of this kind would be very limited in its 
scope. Unfortunately, this plan has often been followed by many of the 
leading technical societies in this country and abroad, in fixing the defi- 
nitions of bituminous substances. 

A far better method consists m basing the definition upon the inherent 
characteristics of the substance, so as to permit of its identification with- 
out necessarily having prior knowledge concerning its origin. 

The four cardinal features forming the basis of nomenclature may be 
further elaborated as follows : 



Origin 



Physical 
Properties 



Native 



Pyrogenous 



Color in Mas3 



TABLE I 

Mineral 

Vegetable 

Animal 

Evaporation (fractional distillation) 
Destructive distillation 
Heating in a closed vessel 
Blowing with air. 

Light (white, yellow or brown) 
Dark (black) 



{Liquid 
Viscous 
Semi-solid 
Solid 



Fracture 



Lustre 



Feel 



Odor 



Volatility 



Fusibility 



Conchoidal 
Hackly 

Waxy 

Resinous 

Dull 

Adherent 
Non-adherent 
Unctuous (waxy) 

Oily (petroleum-like) 
Tarry 

Volatile 
Non-volatile 

Fusible 

Difficultly fusible 

Infusible (melts only with decomposition) 



CLASSIFICATION OF BITUMINOUS SUBSTANCES 21 

TABLE 1— Continued 
_ . .... f Non-mineral constituents in carbon disulphide 

\ Distillate at 300 to 350° C. in sulphuric acid (i.e., " sulphonation residue") 

{Hydrocarbons (compounds containing carbon and hydrogen) 
Oxygenated bodies (compounds containing carbon, hydrogen, and oxygen) ^ 
Crystallizable parafEnes (crystallize at low temperatures) 
Mineral matter (inorganic substances). 

In Table II on p. 22 the principal types of bituminous substances 
are classified according to the features enumerated in Table I. 

The definitions which follow are based upon this classification. 
Although reference is made to the origin of the substance, nevertheless, 
this is but incidental, and with the exception of the generic terms, the 
definitions would be explicit even though this feature were omitted. 

Bituminous Substances.^ A class-of native and pyrogenous^ substances 
containing bitumens or pyrobitumens, or resembling them in their 
physical properties. 

Note. This definition includes bitumens, pyrobitumens, pyrogenous distillates 
(pyrogenous waxes and tars) and pyrogenous residues (pitches and pyrogenous asphalts). 

Bitumen.^ A generic term applied to native substances of variable 
color, hardness and volatility; composed of hydrocarbons substantially 
free from oxygenated bodies; sometimes associated with mineral matter, 
the non-mineral constituents being fusible and largely soluble in carbon 
disulphide; and whose distillate fractioned between 300 and 350° C. 
yields considerable sulphonation residue. 

Note. This definition includes petroleums, native asphalts, native mineral waxes 
and asphaltites. 

Pyrobitumen.^ A generic term, applied to native substances of dark 
color; comparatively hard and non-volatile; composed of hydrocarbons, 
which may or may not contain oxygenated bodies; sometimes associated 
with mineral matter, the non-mineral constituents being infusible and 
relatively insoluble in carbon disulphide. 

1 The scope of the word "bituminous" is based on the commonly accepted interpretation of 
the suffix "ous," signifying: (1) to contain; (2) to resemble, to partake of the nature, to have 
the qualities (e.g., silicioiis: containing silica or resembling silica; resinous: containing or resembling 
resin; oleaginous: containing or resembling oil; calcareous: containing or resembling lime). Simi- 
larly, the word "bituminous" is construed to include substances, either containing more or less 
bitumen (or pyrobitumen), or else resembling them in their appearance or qualities. 

* The expression "pyrogenous" implies that the substance was produced by means of heat 
or fire. 

' The interpretation of the term "bitumen" as employed in this treatise is entirely disassociated 
from the idea of solubility (in certain solvents for hydrocarbons), and has no connection whatsoever 
with the inappropriate expression "total bitumen," used in many contemporary text-books to 
designate the amount soluble in carbon disulphide, and which perhaps is largely responsible for 
the existing confusion in the terminology. 

^ The expression "pyrobitumen" implies that the substance when subjected to heat or fire 
will generate, or become transformed into bodies resembling bitumens (in their solubility and 
physical properties). 



22 



ASPHALTS AND ALLIED SUBSTANCES 



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Si 






CLASSIFICATION OF BITUMINOUS SUBSTANCES 23 

Note. This definition includes the asphaltic and non-asphaltic pyrobitumens, and 
their respective shales. 

Petroleum. A species of bitumen, of variable color, liquid consistency, 
having a characteristic odor; comparatively volatile; composed of hydro- 
carbons, substantially free from oxygenated bodies; soluble in carbon 
disulphide; and whose distillate fractioned between 300 and 350° C, 
yields considerable sulphonation residue. 

Note. This definition includes non-asphaltic, mixed-base and asphaltic petroleums. 

Mineral Wax. A term applied to a species of bitumen, also to certain 
pyrogenous substances; of variable color, viscous to solid consistency; 
having a characteristic lustre and unctuous feel; comparatively non- volatile; 
composed of hydrocarbons, substantially free from oxygenated bodies; 
containing considerable crystallizable paraffines; sometimes associated 
with mineral matter, the non-mineral constituents being easily fusible and 
soluble in carbon disulphide. 

Note. This definition is applied to native mineral waxes and pyrogenous waxes. 
Native mineral waxes include ozokerite, montan wax, etc. Pyrogenous waxes include 
the solid paraffines separated from non-asphaltic and mixed-base petroleums, peat 
tar, lignite tar and shale tar. 

Asphalt. A term applied to a species of bitumen, also to certain pyro- 
genous substances of dark color, variable hardness, comparatively non- 
volatile; composed of hydrocarbons, substantially free from oxygenated 
bodies; containing relatively little to no crystallizable paraffines; some- 
times associated with mineral matter, the non-mineral constituents being 
fusible, and largely soluble in carbon disulphide; and whose distillate 
fractioned between 300 and 350° C, yields considerable sulphonation 
residue. 

Note. This definition is applied to native asphalts and pyrogenous asphalts. 
Native asphalts include asphalts occurring naturally in a pure of fairly pure state, also 
asphalts associated naturally with a substantial proportion of mineral matter. Pyro- 
genous asphalts include residues obtained from the distillation, blowing, etc., of petro- 
leums (e.g., residual oil, blown asphalts, residual asphalts, sludge asphalt, etc.), also 
from the pyrogenous treatment of wurtzilite (e.g., wurtzihte asphalt). 

Asphaltite. A species of bitumen, including dark colored, compara- 
tively hard and non-volatile solids; composed of hydrocarbons, substan- 
tially free from oxygenated bodies and crystallizable paraffines; some- 
times associated with mineral matter, the non-mineral constituents being 
difficultly fusible, and largely soluble in carbon disulphide ; and whose dis- 
tillate fractioned between 300 and 350° C. yields considerable sulphonation 
residue. 

Note. This definition includes gilsonite, glance pitch, and grahamite. 



24 ASPHALTS AND ALLIED SUBSTANCES 

Asphaltic Pyrobitumen. A species of pyrobitumen, including dark 
colored, comparatively hard and non- volatile solids; composed of hydro- 
carbons, substantially free from oxygenated bodies', sometimes associated 
with mineral matter, the non-mineral constituents being infusible and 
largely insoluble in carbon disulphide. 

' Note. This definition includes elaterite, wurtzilite, albertite, impsonite and the 
asphaltic pyrobituminous shales. 

Non-asphaltic Pyrobitumen. A species of pyrobitumen, including 
dark-colored, comparatively hard and non-volatile solids; composed of 
hydrocarbons, containing oxygenated bodies', sometimes associated with 
mineral matter, the non-mineral constituents being infusible, and largely 
insoluble in carbon disulphide. 

Note. This definition includes peat, lignite, cannel coal, bituminous coal, anthra- 
cite coal, and the non-asphaltic pyrobituminous shales. 

Tar. A term applied to pyrogenous distillates of dark color, liquid 
consistency; having a characteristic odor; comparatively volatile; of 
variable composition, sometimes associated with carbonaceous matter, 
the non-carbonaceous constituents being largely soluble in carbon disul- 
phide; and whose distillate fractioned between 300 and 350° C, yields 
comparatively little sulphonation residue. 

Note. This definition includes the volatile oily decomposition products obtained 
from the pyrogenous treatment of petroleum (water-gas tar and oil-gas tar), bones 
(bone tar), wood and roots of coniferse (pine tar), hardwoods, such as oak, maple, 
birch, and beech (hardwood tar), peat (peat tar), lignite (lignite tar), bituminous coal 
(gas-works coal-tar, coke-oven coal-tar, blast-furnace coal-tar, producer-gas coal-tar, 
etc.), and pyrobituminous shales (shale tar). 

Pitch. A term applied to pyrogenous residues, of dark color, viscous 
to solid consistency; comparatively non-volatile, fusible; of variable 
composition; sometimes associated with carbonaceous matter, the non- 
carbonaceous constituents being largely soluble in carbon disulphide; 
and whose distillate fractioned between 300 and 350° C. yields com- 
paratively little sulphonation residue. 

Note. This definition includes residues obtained from the distillation of tars 
(oil-gas-tar pitch, water-gas-tar pitch, bone-tar pitch, wood-tar pitch, peat-tar pitch, 
lignite-tar pitch, gas-works coal-tar pitch, coke-oven coal-tar pitch, blast-furnace coal- 
tar pitch, producer-gas coal-tar pitch, and shale-tar pitch) ; also from the distillation of 
fusible organic substances, the process having been terminated before the formation 
of coke (rosin pitch and fatty-acid pitch). 

It will be noted that the terms "mineral wax" and "asphalt" are each applied 
indiscriminately to native and pyrogenous substances. This is due to the fact that 



CLASSIFICATION OF BITUMINOUS SUBSTANCES 25 

at the present time it is practically impossible to distinguish between certain native 
and pyrogenous asphalts or mineral waxes, either by physical or chemical means. It 
is probable that some method may be discovered for accomplishing this, in which 
event it would be of decided advantage to frame separate definitions to distinguish 
between native and pyrogenous substances respectively. With the knowledge avail- 
able at present, however, this cannot readily be accomplished. We must be content, 
therefore to apply the term "asphalt" and "mineral wax" both to native substances 
and to manufactured (pyrogenous) products. 

In many of the early classifications, natural gas and marsh gas were included 
within the scope of the term "bitumen." As this stretches the meaning to an 
abnormal extent, the author deems it inadvisable to include natural gases in the 
definitions and classification given in this book. 

The term "maltha," frequently found in contemporary classifications to desig- 
nate the softer varieties of native asphalt, has been omitted for the sake of brevity. 

The preceding definitions enable us to arrive at the following classi- 
fication of bituminous substances, in which are included the most impor- 
tant members recognized commercially. 



26 



ASPHALTS AND ALLIED SUBSTANCES 



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CLASSIFICATION OF BITUMINOUS SUBSTANCES 



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CHAPTER III 

CHEMISTRY OF BITUMINOUS SUBSTANCES 

STRUCTURAL FORMULAS OF THE MOST IMPORTANT PURE 
CHEMICAL SUBSTANCES PRESENT IN BITUMINOUS 
COMPLEXES 

Bituminous substances are complex mixtures of chemical compounds containing 
the elements carbon and hydrogen in varying proportions and combined in differ- 
ent ways. These compounds may also contain the elements oxygen, sulphur, and 
nitrogen. Certain bituminous substances and especially those found in nature, con- 
tain more or less extraneous mineral matter. Carbon and hydrogen, however, are 
present in the chemical compounds contained in all types of bituminous substances. 
These two elements have the properties of forming a bewildering number of com- 
binations — in fact more than any other two elements. Substances composed of car- 
bon and hydrogen are termed " hydrocarbons." 

Each element has the power of combining with other elements in certain def- 
inite ratios. The combining power of the element hydrogen is taken as unity, 
and it is therefore said to have a "valency" of 1. Oxygen is capable of com- 
bining with 2 atoms of hydrogen, forming a molecule of water (H2O), and therefore 
has a valency of 2. Similarly, carbon can combine with four atoms of hydrogen, 
and has a valency of 4. These valencies may be pictured mentally as bonds or 
joinings, holding the elements together. For the sake of convenience, they are 
represented graphically by dashes, thus: 

H— ; 0= or — O— ; C= or =C= or — C— . 

I 

Carbon atoms, moreover, have the property of uniting with one another. When 
but two carbon atoms combine, the union may occur in three ways: 

(1) Two carbon atoms may unite with a single valency joining them together, 
leaving three free valencies for each carbon atom, or a total of six, illustrated as follows: 

=C— C=; simplified as ^C— C=. 

(2) The carbon atoms may be bonded together with two valencies, leaving four 
free valencies, thus: 

=C=: =C=; simplified as =C=C=. 

(3) The carbon atoms may be joined together by three valencies, leaving but 
two uncombined valencies, thus: 

— C= =C — ; simplified as — C=C — . 

28 



CHEMISTRY OF BITUMINOUS SUBSTANCES 



29 



The free valencies may unite with hydrogen atoms or other carbon atoms, 
forming an endless number of combinations, and constituting a series of hydrocarbons, 

thus: 



H H 

I I 
H— C— C— H 

I I 
H H 

C2H6 Ethane 
(CHs-CHa) 



H H H 

I I I 
H— C— C— C- 

I I I 
H H H 



-H 



C3H8 Propane 
(CHa-CHCHs) 



H H H H 

I I I I 
H— C— C— C— C— H etc. 

I I I I 
H H H H 

C4H10 Butane 
(CHsCHCH-CHa) 



H 
>C=C— H 



C2H4 Ethylene 
(CH2 : CH2) 



H H 

H. I I 

>C=C— C— H 
H/^ I 

H 

CsHc Propylene 
(CH2 :CH-CH3) 



H H H 

Hs. I I I 

>C==C— C— C— H 
W I I 

H H 



etc. 



C4H8 Butylene 
(CH2 : CHCHo-CHs) 



H— C=C— H 



C2H2 Acetylene 
(CH i CH) 



H 

! 
H— C=C— C— H 

I 
H 

C3H4 Allylene 
(CH i CCH3) 



H H 

I I 
H— C=C— C— C— H etc. 

I I 
H H 

C4H6 Ethylacetylene 
(CH i CCH2CH3) 



These are termed "open chain hydrocarbons/' because all the carbon atoms 
are connected together in a straight line. The first three examples, ethane, pro- 
pane, and butane, are said to be members of a saturated series because no two 
carbons are held together by more than one valency, or in other words, all the 
carbon atoms are "saturated" or combined with hydrogen. This particular series 
of hydrocarbons has been named "parafRnes," because the various members are 
ordinarily found in paraffinaceous petroleum and paraffine wax. In each member 
there exists a definite ratio between the number of carbon and hydrogen atoms 
respectively. For each atom of carbon present, we find two more than twice as 
many of hydrogen atoms. The paraffine series is accordingly represented by the 
general formula CnH2n+2 ir. which n may range from 1 in the lowest member 
CH4, to as high as 60 in CeoHioo. 

The three substances, ethylene, propylene, and butylene, similarly belong to 
an open chain series of hydrocarbons known as the "olefines" having the general 
formula CnH2n- Since all the carbon valencies are not combined or satiated with 
hydrogen, this series is known as an "unsaturated" one. 

The three substances, acetylene, allylene, and ethyl acetylene belong to the 
unsaturated "acetylene series" represented by the general formula CnH2n-2. The 
acetylene series is obviously more unsaturated than the defines. Similarly, we 
have the diolefine series which has the same general formula as the acetylenes, 
namely CnH2n-2, but which is distinguished from the latter by having two double- 
bonded carbon groups instead of one triple-bonded group. These will be described 
in greater detail later. 



30 ASPHALTS AND ALLIED SUBSTANCES 

The olefinacetylene series (also known as the valylene series) is represented 
by the general formula CnH2n-4, characterized by the presence of both doubly- 
and triply-bonded carbon groups. 

The next higher series of unsaturated open chain hydrocarbons is known as 
the diacetylene series CnH2n-6, characterized by two triply-bonded carbon groups. 

Following these we have the CnH2n-8, CnH2ii-io, and the CnH2ii-i2 series in the 
order mentioned. All of these are found in petroleum. It is highly probable that 
hydrocarbon series of still higher order exist in bituminous substances, but no 
means have as yet been devised to isolate them. 

It should be borne in mind that two or more substances may have the same 
number of carbon and hydrogen atoms, and yet be constituted differently struc- 
turally. Thus, the substance butane, CdHio may exist in two possible forms, 
termed "isomers." These include "normal butane" shown above, and the so- 
called "isobutane" also known as "trimethylme thane," shown diagrammatically as 
follows: 

H 



H— C— H 



c H H Isobutane or Trimethylmethane 

! ! CH3-CH(CH3)2 

H— C C C— H 

III 
H H H 

In a similar manner, the substance "butylene" may occur in three isomers, 
all having the same general formula C4H8, as follows: 

Butylene CH2 : CHCHo-CHs as shown above; 

Pseudobutylene CH3 • CH : CH • CH3; and 
Isobutylene CH2 : C(CH3)2. 

Similarly, ethylacetylene (crotonylene), C^He, occurs in another isomeric form, 
dimethylacetylene, CH3-C • C-CH3. 

In addition to the open-chain hydrocarbons, there occur "cyclic" or "ring" 
hydrocarbons in which the carbon atoms are joined together in a circle, in both 
the saturated and unsaturated forms. The saturated cyclic hydrocarbons are known 
as "polymethylenes." These may in turn be divided into two classes, namely, 
those consisting of but one ring or cycle, and those consisting of more than one 
ring or cycle. The former are termed "naphthenes" or "monocyclic polymethyl- 
enes," and the latter "poly cyclic polymethylenes." The poly cyclic polymethylenes 
may be further grouped into dicyclic polymethylenes, tricyclic polymethylenes, etc. 
Unsaturated cyclic hydrocarbons are grouped into monocyclic and polycyclic series, 
known as "cyclic olefines," ''terpenes," "benzenes," etc. 

We will now consider the individual hydrocarbon series: 

OPEN CHAIN HYDROCARBONS 

CnH2n+2 Series — Saturated — Single Bonds — "Paraffines" 

The various members of this series are shown in Table IV on p. 31: 
As already stated, butane has two isomers, similarly pentane occurs in three 
isomers, hexane in six, heptane in nine, octane in eighteen, and finally tridecane 
in 802 isomers. It follows therefore that as we ascend the scale, the number of 
possible isomers increases rapidly. 



CHEMISTRY OF BITUMINOUS SUBSTANCES 



31 



TABLE IV.— CnHjn+i SERIES— "PARAPFINES— SATURATED— SINGLE BONDS 



Name. 



Formula. 



Melting- 
point, 
Deg. C. 



Boiling- 
point, 
Deg. C. 



Gaseous 

Methane 

Ethane 

Propane 

Normal Butane 

Trimethyl Methane 

Liquid 

Normal Pentane 

Dimethyl-ethyl Methane. . 

Tetramethyl Methane . . . . 

Normal Hexane 

Methyl-diethyl Methane.. 

Dimethyl-propyl Methane 

Di-isopropyl 

Trimethyl-ethyl Methane . 

Heptane 

Octane 

Nonane 

Decane 

Undecane 

Dodecane 

Tridecane 

Tetradecane 

Pentadecane 

Hexadecane 

Heptadecane 

Solid 

Octodecane 

Nonadecane 

Eicosane 

Heneicosane 

Docosane 

Tricosane 

Tetracosane 

Pentacosane 

Hexacosane 

Heptacosane 

Octocosane 

Nonocosane 

Triocontane 

Hentriocontane . . 

Dotriacontane 

Tritriacontane 

Tetratricontane 

Pentatriacontane 

Dimyricyl 



CH4 

CzHt CHsCH3 

C3H8 CH3-CHj-CH3 

C4H10 CH0CH2CH2CH3. 
C4H10 CHs-CHtCH3)2 



C5H12 
C5H12 
C6H12 
CeHu 
CoHm 
CeHi* 
CeHi* 
CeHu 
CrHw. 
CsHiS. 

C»H20 . 

C10H22. 

C11H24. 

C12H26. 
CisHjs. 
C14H30 . 
C15H32. 
C16H34. 
C17H36. 

C18H38. 
C19H40. 



CH3(CH2)3CHs 

CHsCH2-CH(CH3)2.. 

C(CH3)4 

CH3-(CHj)4-CH3 

CH3-(C2H5)2CH 

CH3-(CH2)2-CH(CH3)2 
(CH3)2.(.CH)2(CH3)2 .. 
CH3CH2-C(CHj)3.... 



C20H42 . 
C21H44. , 
C22H46. . 
C23H48. . 
C24H50. . 

C25H52. . 

C26H54. . 

C27H56. . 

C28H55. . 

C29H60. . 
C30H62. , 
C31H64. . 
C32H66. . 
C33H68. . 
C34H70. . 

C35H72. . 

Ceo H 122 . 



186 
172 
195 
135 



- 51 

- 31 

- 26 

- 12 

- 6 
+ 5 

10 
18 
22 

28 
32 

37 

40 
44 
48 
51 
53 
56 
58 
60 
62 
64 
66 
68 
70 
72 
75 
102 



At 760 mm. 
-165 

- 93 

- 45 
+ 1 

- 17 



+ 45 
+ 98 

125 

150 

173 

195 

214 

234 

252 

270 

287 

303 

317 
330 
At 15 mm, 
205 
215 
225 
234 
243 



270 



302 
310 



331 



The specific gravity, boiling- and melting-points increase with the molecular 
weight. In the case of isomers, those of normal structure have the highest boiling- 
points. The higher members are volatile without decomposition only under reduced 
pressure. The same general rules hold true with other hydrocarbon series. 

The gaseous members of the paraffine series are found in marsh gas, natural 
gas and coal gas. The liquid members are associated together in certain forms of 



32 



ASPHALTS AND ALLIED SUBSTANCES 



petroleum, such as Pennsylvania petroleum. The solid members occur in ozokerite 
and the various types of paraffine wax. 

Paraffinaceous petroleum is composed of a mixture of the individual members 
of the paraffine series in varying proportions. It is a difficult matter to isolate 
the individual hydrocarbons in their pure state. For commercial purposes, petro- 
leum is separated by distillation into various liquids or solids sold under the trade 
names of gasolene, benzine, naphtha, kerosene, lubricating oil, paraffine oil, paraf- 
fine wax^ petroleum asphalt, etc. Each of these consists of complex mixtures of 
the individual hydrocarbons in indefinite proportions. 

Paraffine wax contains solid hydrocarbons of high boiling-point (about 300° C), 
and ozokerite solid hydrocarbons ranging from C24H60 upward. 



CnH2n Series — Unsaturated — One Double Bond— " Olefines " 
The well-known members of this series are shown in the following table: 

TABLE v.— CnHjQ SERIES— "OLEFINES"— UNSATURATED— ONE DOUBLE BOND 



Name. 


Formula. 


Melting- 
point. 
Deg. C. 


Boiling- 
point. 
Deg. C. 


Gaseous: 

Ethylene 


C2H4 CH2 : CH2 


-169 .~ 


at 760 mm. 
— 103 


Prnnvlpne 


CsHc CH3-CH:CHx 


—50 


gutylene 


C4H, 

CjHs-CH : CH2 






Ethyl-ethylene 


— 5 


CHa-CH : CHCHs 

(CHj)2C : CH2 




+ 1 
— 6 


Isobutylene 

Liquid: 

Amylene 


C5H10 

CH3-(CH2)2CH : CHj. . . 

(CH3)2-CHCH : CH2 . . 

CHsCH :CHC2H5.... 

(CH3)(C2H6)C :CH2.... 

(CH3)2C :CH(CH3) 

CeHiz 









+39 
+20 
36 
31 
36 
69 


Isopropyl-ethylene 

Sym. Methyl-ethyl-ethylene 

Unsym. Methyl-ethyl-ethylenc. . . 

Trimethyl-ethylene 

Hexvlene {n) 




C7H14 




95 




CsHie 




122 


Nonylene 


Cgliie 




153 








172 


Undecylene . ^ ^ . . 


C11H22 




195 


Dodecvlene . , , 




-31 


213 


Tridecylene , 


C13H26 


233 


Tetradecylene 


Cl4H,8 

CieHsj 


-12. 

+ 4 . 
+ 12 
+ 18 


275 




CnHai , , . 






CisHsd 






C20H40 . . 


314 


Solid: 


C27H64 


+58- 
+62 




Melene 


C30H60 


375 









These are present in American petroleums in very small amounts. Certain 
members have been identified in Canadian petroleums, also in shale oil. The higher 
members of the olefine series occur in isomeric forms in the same way as the paraffines. 



CHEMISTRY OF BITUMINOUS SUBSTANCES 



33 



CnH2n-2 Series — Unsaturated — One Triple Bond — "Acetylenes" 
The best known members of this series are included in the following table: 

TABLE VI.— CnH2n-2 SERIES— "ACETYLENES"— UNSATURATED— ONE TRIPLE 

BOND 



Name. 


Formula. 


Boiling- 
point, 
Deg. C. 


Gaseous: 

Acetvlenc 


C2H2 CH : CH 
C3H4 CHaC : CH 

C4H6 CHaC : CCHj 




AUylene 




Liquid: 

Crotonylene 


27 


Ethyl-acetylene 


C4H6 C2H5 • C ! CH 


18 


Methyl-ethyl-acetylene 


CsHs CHs • C : C • CsHs 


55 




CsHs CH3CH2CH2C : CH 

CsHs (,CH3)2CH C : CH 


48 


Isopropyl-acetylene 


28 


Alethyl-n-propyl-acetylene 


CeHio CH3-C I C(CH2)2CH3. 


84 







The lower members have not been identified in any petroleums, although several 
of the higher members are found in Texas, Louisiana, and Ohio oils, and are also 
present in coal tar. 

CnH2n-2 Series — Unsaturated — Two Double Bonds — "Diolefines" 

The more important members of this series are shown in Table VII. 

TABLE VII.— CnHjn-J SERIES— "DIOLEFINES"— UNSATURATED— TWO DOUBLE 

BONDS 



Name. 


Formula, 


Boiling- 
point, 
Deg. C. 


Allylene (Propadiene) 

Divinyl (Erythrene) 

Piperylene (a-Methylbutadiene) 


CH2 : C : CHj. 

CH2 :CHCH :CH2 

CH2 : CH CH : CH CHs . 


Gas 

- 3 

42 


Isoprene (^-Methylbutadiene) 


CH2 :CH-C(CH3) :CH2 

CH2 : C(CH3) -CCCHa) : CH, 

(CH3)2C : CH -CCCHs) : CH2 

CH2 : CHCHz-CHiCH : CH». 

CH2 : C(CH3) -CHa-CHaCCCHa) : CH, ... 
(CH3)2C : CH.CH2-CH2-C(CH3) : CII2. . . 
CH2 -.CH-CHaCH -.CHCHzCHiCHs. 


35 

71 


1-1-3-Trimethylbutadiene 

Diallyl 

2-5-Dimethyl-l-5-hexadiene 

l-l-5-Trimethyl-l-5-hexadiene 


93 

59 

137 

141 

126 







These occur in tars and certain petroleums, 

CDH2n-4 Series — Unsaturated — One Double and One Triple Bond — 

* ' Olefinacetylenes ' ' 
Individual membei^ of this series have been identified in Ohio petroleum, also 
also in certain types of California petroleum. 

CnH2n-4 Series — Unsaturated — Three Double Bonds — " Polyolefines " 
To this series belong the hydrocarbons known as "terpenes," none of which 
is present to any appreciable extent in bitumens, tars, or pitches. 



34 



ASPHALTS AND ALLIED SUBSTANCES 



CnHjn-8 Serie6 — Unsaturated — Two Triple Bonds — "Di acetylenes" 

This series is also relatively unimportant, and includes diacetylene, H • C : C • C i 
CH, dipropargyl, CH '. C-CHrCHaC i CH (also known as hexadine), dimethyldi- 
acetylene, CHjC i C-C 1 CCH3, etc. 

CYCLIC HYDROCARBONS 

CnHzn Series — Saturated — Single Bonds — Monocyclic — "Naphthenes" also 
Called "Cycloparaffines" or "Polymethylenes." 
The following constitute the more important members of the naphthenes: 

TABLE VIII.— CnHsn— SERIES— "NAPHTHENES" OR "CYCLOPARAFFINES" OR 
" POLYMETHYLENES "—MONOCYCLIC— SATURATED— SINGLE BONDS 



Name. 



Formula. 



Melting- 
point, 
Deg. C. 



Boiling- 
point, 
Deg. C. 



Cyclopropane (Tri methylene) , 



Methylcyclopropane . 



Dimethyl-1-l-cyclopropane . 



Trimethyl-l-l-2-cyclopropane . 



TrimethyI-l-2-3-cyclopropane . 



Cyclobutane (Tetramethylene). 



Methylcyclobutane . 



Ethylcyclobutane. 



Cyclobutyldiethylmethane. 



Cyclopentane (Pentamethylene). 



/CH2 

ch/ I 

_XHj 

/CHj 
CH3— CH 

^CHa 
CHj\ /CHi 

><l 

CH3/ ^CHi 
CH3\ /CHCHj 

>c<l 

CHj/ XH2 

yCH-CHj 

CH3— CH 

^CHCHb 

CH2— CH2 

I I 

CH2— CH2 

CHaCH— CHj 

I I 

CH2— CHi 

CjHe-CH- CHi 

I I 

CH2— CHj 



.C2H6 



CH2— CH— CH 

I I 

CH2— CH2 

CH2— CH2\ 



\, 



C2HB 



>CH2 



CH2— CH2 



126 



Below -80 



Below 



-35 



+ 4 



21 



56 



65 



11 



40 



72 



153 



50 



CHEMISTRY OF BITUMINOUS SUBSTANCES 

TABLE \IIl— Continued. 



35 



Name. 


Formula. 


Melting- 
point, 
Deg. C. 


Boiling- 
point, 
Deg. C. 




1 pCHCHi 

ch^ch/ 




72 








CH2— CH2\ /CHa 

1 >c< 

CH2— CHz'^ ^CHi 




88 








DimethyI-l-2-cyclopentane 


CHi— CHzK 
1 ^CH-CHa 
CH2— CH / 




93 








CHs 






Di methyl- 1-3-cyclopentane 


CH»— CH2\ 
1 >CH-CH8 
CH — Ch/ 




91 










CHs 






Methyl-l-ethyl-2-cycIopentane 


CH2-CH,v 
1 ^CH-CHi 
CH2— CH ^C2H6 




124 








MethyI-1 -ethyl-3-cyclopentane 


CH2— CH2\ 
1 ^CHCHs 
C2H6— CH— CH2 '^ 




120 








Cyclohexane (Hexamethylene) 


CHz-CHz— CHj 

1 1 
CH^CH2— CH2 


+ 6 


81 


Methylcyclohexane 


CH3— CH — CH2— CH2 

1 1 
CH2— CH2~CHa 




100 








Dimethyl-1-l-cyclohexane. ... 


CH3\ 

}C CH2— CH2 

CH3^ 1 1 

CH2— CH2— CHa 




117 










CHa CHs 






Dimethyl-l-2-cyclohexane 


CH — CH — CHj 




126 




! 1 

CH2— CH»— CHi 








CHs CHs 






Dimethyl-l-3-cyclohexane 


CH — CH2— CH 




119 




1 1 
CH2— CHt— CH, 






Dimethyl-l-4-cyclohexane 


CH3— CH — CH:--CH2 

CH2— CHr-CH— CHs 




120 








Ethylcyclohexane 


C2H5— CH — CH2— CHj 

1 1 
CH2— CH^CHj 




130 









36 



ASPHALTS AND ALLIED SUBSTANCES 

TABLE YUI— Continued. 



Name. 


Formula. 


Melting- 
point, 
Deg. C. 


Boiling- 
point, 
Deg. C. 




CH3V 

>C CHj— CH-CHs 

CH3/ 1 1 
, CH2— CH2— CH2 

CH3 CH3 

CH — CH —CHj 

1 ! 

CH2— CH2— CH— CHa 
CH3— CH — CH2— CH— CH3 

1 1 
CH2— CH — CH2 

CHi 

CHa C2H5 

CH — CH — CHj 

1 1 

CH2— CH2— CHj 

CH3— CH — CH2— CH— C2n5 

1 1 
CH2— CH2— CH2 

CHj- CH — CH2— CH2 
1 1 
CHi— CH2— CH— C2H5 

C3H7— CH — CH2— CH2 

1 1 
CH^CH2— CH2 

CH3— CH — CH2— CH2 

CH2— CH2— CH— C3H7 
CH3— CH — CH2— CH— C2H6 

1 ! 

CH2— CH-— CH— C3H7 
C2H5— CH — CH2— CH— C2H5 

1 i 
CH2— CH2— CH2 

CH2— CHj— CH2\ 
1 >CHj 
CHj— CHj— CHj/ 

CHj— CHj— CH2— CHj 

1 1 

CH2— CHj— CHj— CHj 
CHj— CHj— CHj— CHjv 

1 >CH2 
CHj— CHi— CH2— CHj/ 




137 


Trimethyl-l-2-4-cyclohexane 




143 






138 


Methyl-l-ethyl-2-cyclohexane 




151 


Methyl-l-ethyl-3-cyclohexane 

Methyl-l-ethyl-4-cyclohexane 

Propylcyclohexane 




149 




150 




153 


Methyl-l-isopropyl-4-cyclohexane 
(Menthane) 




169 


Methyl-l-ethyl-3-isopropyl-4-cyclo- 




207 


Diethyl-l-3-cyclohexane 




170 


Cycloheptane (Suberane) 




117 


Cyclo-octane (Octomethylene) 


11 


148 
171 









CHEMISTRY OF BITUAIINOUS SUBSTANCES 



37 



These occur largely in Russian (Baku) petroleum, in American mixed-base, and 
asphaltic petroleums (including Ohio, California and Canadian), in certain South 
American petroleums (Peru and Colombia) and in Borneo petroleum. 

CnH2n-2 Series — Saturated — Single Bonds — Polycyclic — "Polycyclic 

POLYMETHYLENES " 

The most important members of this series are given in the following table: 

TABLE IX.— CnHjn-j SERIES— "POLYCYCLIC POLYMETHYLENES"— POLYCYCLIC— 
SATURATED— SINGLE BONDS 



Name. 



Dihydropinene (Pinane) 

Trimethyl-2-7-7-bicyclo-l-l-3-hep- 
tane 



Trimethyl-l-7-7-bicyclo-l-2-2-heptane 
(Camphane) 



Bicyclononane. 



Dekahydronaphthalene 



MethyI-l-bicyclo-l-3-3-nonane . 



Formula. 



CH:. 



CH CH— CH3 

CHz >CH2 



CH3 CH CHj 



CH2- 



CHa 
-C— 



-CH2 



CH2- 



-CH2 



CHj— C— CH3 

I 
-C- 

H 



CH2— CH2— CH— CH2\ 
i I >CH2 

CH2— CH2— CH— CH/ 

CH2— CHj— CH— CH>— CH2 

I !' I 

CH2— CH2— CH— CH2— CH2 



CH2 



CHj 

— C- 

1 



-CH2 



CH2 CH2 CHj 

I 1 I 

CH2 CH— CH2 



Melting- 
point, 
Deg. C. 



153 



Boiling- 
point, 
Deg. C. 



116 



IGl 



163 



188 



177 



These hydrocarbons are usually associated with the monocyclic CnH2n Series. 

CnH2n-2 Series — Unsaturated — One Double Bond — Monocyclic — "Cyclo- 

Olefines" 

These include cyclo-ethylene, C4H6, CH=CH and cyclo-propylene, CeHg, 
CH=CH 1 I 

/ \ CH2-CH2 

CH2 — CH2 — CH2 which occur largely in Texas oils and in certain asphalts. 

CdHoq-i Series — Unsaturated — Two Double Bonds — Monocyclic — "Terpenes" 

These include the substances limonene, dipentene, terpinolene, terpinene, 
sylvesterene,. etc., and are found in Java, Sumatra, Baku, Galicia and Texas 



38 



ASPHALTS AND ALLIED SUBSTANCES 



(Beaumont) petroleums in relatively small amounts. They also constitute the so- 
called ''essential oils." 

CnH2n-4 Series — Saturated — Single Bonds — "Polycyclic Polynaphthenes 

These are found in Texas (Beaumont), Louisiana, Cahfornia, and Ohio petro- 
leums, of which the principal members are shown in Table X. 



TABLE X.— CnH2n-4 SERIES— "POLYCYCLIC POLYNAPHTHENES"— POLYCYCLIC 
SATURATED— SINGLE BONDS 


Name. 


Formula. 


Melting- 
point, 
Deg. C. 


Boiling- 
point, 
Deg. C. 




CH2 CH, 

1 1 






Perhydroacenaphthene 


1 1 
CHjCH- CHCH -CHi 




235 


I 1 1 
CHjCHjCHCHjCHi 








CHj • CHj . CH • CH • CHj . CHi 

1 II 1 








1 II 1 
CH, . CHi • CH • CH • CHj • CHj 

\/ 
CHs 




230 










CH, • CH, • CH— CH • CH, • CH, 

1 II 1 






Perhydrophenanthrene 


1 II 1 
CH,CH,CH CHCHjCH, 




272 




1 ! 

CH2— CH, 








CH, • CH, • CH • CH, • CH . CH, • CHj 

1 1 1 1 
CH, • CH, . CH • CH, • CH • CH, • CH, 


88 


270 








/CH,— CH— CH— CH,x 

CH,/ 1 1 )>CH, 

^CH,— CH— CH— CH,/ 


9 









CnHzn-B Series — Unsaturated — Three Double Bonds — Monocyclic- 

" Benzenes" 

The benzenes constitute one of the most important series of hydrocarbons, and 
form the basis for many valuable organic compounds, including the "coal tar" 
dyes and drugs. The lowest member of this series is the hydrocarbons benzol or 
benzene, CeHc. Its exact structure is represented by the following diagram: 



H 
H X H 



i 



H 



Which, for the sake of con- 
venience, is abbreviated by the 
following symbol : 







CHEMISTRY OF BITUMINOUS SUBSTANCES 



39 



'^This is known as the '"benzol ring," consisting of six carbon atoms joined 
together with single and double bonds alternately, and each united with a single 
atom of hydrogen. 

The principal members of the benzene series, CnH2n-6, are shown in the follow- 
ing table: 

TABLE XI.— CnHjn-s SERIES— "BENZENES"— MONOCYCLIC— UNSATURATED— 

DOUBLE BONDS 



CeHe 



CeHe Benzol (B.P. =80° C. 



CtHs 



CeHs-CHs Toluol (110°) 



CsHi 



C6H4(CH3)2 Xyloles (3) 
(Ortho=142°; Meta=139°; Para = 138°) 



C6H5-C2H5 Ethyl-benzol (134°) 



C»Hi2 



CcHjCHs): 
Trimethylbenzoles (3) 
1-3-5 =Mesitylene (163°) 
1-2-4 =Pseudocuniene 

(169°) 
1-2-3 =HemimeUithene 
(175°) 



C6H4(CH3)(C2Ht) 

Ethylmethylbenzoles (3) 
(Ethyltoluoles) 



C6H5(CaH7) 
Propylbenzoles (2) 
Normal-propyl-benzole 

(157°) 
Isopropyl-benzole (153°) 



CioHm 



CjH2(CHj)4 

Tetramethylbenzoles (3) 
1-2-4-5 =Durene (190°) 
1-2-3-5 =Isodurene (195°) 
1-2-3-4 =Prehnitol (204°) 



C6H3(CHj)2(C2H5) 

Ethyldimethyl- 

benzoles 
(6 isomers pos- 
sible) 



C6H4(C2H5)2 

Diethylbenzoles 
(3 isomers pos- 
sible) 



C6H4(CH3)(C3H7) 

Methylpropylbenzoles 
(6 isomers possible) 
l-4=Cymene (176°) 



C6H5(C4H9) 

Butylbenzoles 

(4 isomers^ 

possible) 



CuHl6 



C12H18 



C6H(CH3)5 Pentamethylbenzol (231°); C6H5(C5Hn) Amylbenzol; etc. 



C5(CH3)6 Hexamethylbenzol (264°); C6H3(C2H5)3 Triethylbenzol; etc. 



C14H2 



C6H5(C8Hi7) Octylbenzol; C6H2(C2H6)4 Tetraethylbenzol. 



CisHso C6(C2H6)6 Hesaethylbenzol (305°). 



Members of the benzene series are present in coal tars, water-gas tar and 
other high-temperature distillates. Coal tars, however, constitute the most prolific 
source of the benzenes. They are present to a small extent in lignite tar, and 
only in very small quantities in petroleum. Traces have been identified in petro- 
leums obtained from Borneo, Sumatra, Java, Japan, and to a very smaU extent 
in certain varieties from California. 



40 



ASPHALTS AND ALLIED SUBSTANCES 



CnH2n-8 TO CnH2n-30 SeEIES — UNSATURATED — MONOCYCLIC AND POLYCYCLIC 

These are grouped together for the sake of convenience. A brief description 
will be given of the respective series, together with their principal members. 

CnH2n-8 Series, of which the principal member is phenylethelene, CeHs-CH : CH2. 
This series is composed of the benzol nucleus with an unsaturated side chain. 

CnH2n-io Series, of which the principal member is phenylacetylene, CeHj-C '. CH. 
This series is composed of the benzol nucleus with a side chain corresponding to 
the acetylene series. It is not of importance. 

CnH2n-i2 Series, known as the "naphthalenes." 

The principal member of this series is naphthalene, CioHs, which is represented 
graphically as: 



H H 

H i i 

I ii i 

c c c 

^ I I 

H H 



H 



H 



And for the sake of 
brevity, by the symbol: 




Naphthalene has a crystalline structure and a characteristic odor. It is found 
principally in coal tar. Other members of this series are methyl naphthalene, 
CioHv-CHs, dimethyl naphthalene, CioH6(CH3)2, ethyl naphthalene,' Ci.oH 7 -02115, etc. 

CnH2n-i4 Series, known as the ''diphenyls." 

The principal member of this is diphenyl, C12H10, which is represented graphically 
by the following formula: 



The next member of this series is methyl diphenyl, C13H12. The CnH2n-i4 
hydrocarbons also include the acenaphthene series, which is an isomer of the pre- 
ceding. The first member of this series is known as acenaphthene, C12H10, which 
is represented graphically as follows: 



CH2-CH2 



CnH2n-i6 Series, including the diphenylenes of which the fii-st member is flu- 
orene, C13H10: 



C6H4 

I 
CeHi 



)>CHa 



\ 



or 



/\/^^' 



CHEMISTRY OF BITUMINOUS SUBSTANCES 41 

This series also includes the substance known as stilbene (diphenylethylene) 
CeHo-CH ; CH -Cells. 

CnH2n-i8 Series, known as "anthracenes," of which anthracene, C14H10 is the 
principal member. Anthracene may be illustrated graphically by the following 
formula : 




— CH— 



\/ 



Retene is also a member of this series. 

CnH2n-2o Series, of which " fluoranthene, " C15H10 is the principal member. 

CnH2n-22 Series, of w^hich "p\Tene," CieHio, is the principal member. 

CnH2n-26 Series, of w^hich "dinaphthyl," is the principal member. 

CnH2n-28 Series, of which no members have been isolated. 

CnH2n-3o Series, known as the "picenes," of which picene, C22H44, is the prin- 
cipal member. Picene is the highest melting-point hydrocarbon which has been 
isolated. It melts at 364° C, and occurs in lignite tar, coal tar and certain petro- 
leum residues. 

The hydrocarbons of the series CnH2n-8 to CnH2n-3o occur in coal tar, and to 
a smaller extent in lignite tar and petroleum residues. 

OXYGENATED BODIES 

These include the following substances: 

Water, H2O. This occurs in small quantities in all native petroleums and in 
most native asphalts, especially those associated with mineral matter. Water is always 
present in crude tars, being formed by the combination of hydrogen and oxygen 
at high temperatures. 

Alcohols. The principal members are methyl alcohol, CH3OH, also known as 
wood alcohol, which is found in substantial quantities in wood tar, also ethyl alcohol, 
C2H5OH, which is also present, but in very small amounts. 

Acetone, CHs-CO-CHs. This substance and its homologues are found in small 
quantities in wood tar, coal tar, and lignite tar. 

Fatty Acids. Acetic acid, CHs-COOH, is present in W'Ood tars, and particularly 
those derived from hard woods. Acetic acid belongs to the series CnH2n+i'C00H. 
The higher melting-point acids of this series including palmitic acid, CH3(CH2)m-COOH, 
stearic acid, CH3(CH2)i6-COOH, and the corresponding esters and lactones are 
found in fatty-acid pitches. 

Resin Acids. These are found in pine tar and pine-tar pitch. The composition 
of these acids has not yet been definitely determined. They are also present to 
a large extent in resin pitch. 

Phenols. The important members of this class of substances are phenol or 
carbolic acid, CgHa-OH, cresol or methyl phenol, CH3 -06114 -OH, of which there are 
three isomers. These and the higher members of this series are present in coal 
tar and lig.iite tar. 

OXYGENATED BODIES OF UNKNOWN COMPOSITION 

Many substances containing oxygen of which the exact composition has not yet been 
determined are present in the nou-asphaltic pyrobitumens, also to a smaU extent in 
tars, pitches, and asphaltites. 



42 ASPHALTS AND ALLIED SUBSTANCES 

NITROGENOUS BODIES 
Ammonia, NH3, and ammonium compounds are found in coal tar. 



I ] 

Pyridine, CsHs-N or ^N'^^, and derivatives of pyridine including methyl pyri- 
dine (also known as picolin, CH3-C5H4-N), dimethyl pyridine, etc., are found in 
coal tar, lignite tar, petroleum asphalts and pitches. 

Quinoline, CaHvN, and its derivatives are also present in these materials. 

NITROGENOUS BODIES OF UNKNOWN COMPOSITION 

These are present in petroleums, asphalts, pyrobitumens, tars and pitches, in rela- 
tively small quantities. 

SULPHURATED BODIES 

The exact chemical composition of the substances containing sulphur has not 
yet been thoroughly investigated. There are, however, numerous sulphurous com- 
pounds in bitumens, pyrobitumens, tars and pitches, including the mercaptanes, 
thiophenes, and their derivatives, also substances of analogous composition. Small 
amounts of hydrogen sulphide, H2S, are found associated with petroleum and 
asphalt, and in the distillates of coal and lignite. 

It will be gathered from the preceding that the chemistry of bituminous sub- 
stances is very complicated, due to the fact that no commercial product has a 
definite composition, but consists of mixtures of numerous chemical substances in 
varying proportions. At the present time certain of these substances have been 
identified, but there is still a vast amount of work to be done in arriving at the 
exact composition of the individual chemical bodies present in bituminous sub- 
stances. Although comparatively Httle is known regarding the exact chemical 
substances present in coals and asphalts, the composition of petroleum and 
various tars has been largely unravelled. Hundreds of definite chemical substances 
have been identified in petroleum, and hundreds have been separated from coal 
tar. No two petroleums are alike in composition. In some, certain chemical sub- 
stances predominate, in others they are absent, or present in smaller amounts. 
The same holds true with tars, pitches, and asphalts. In certain cases, comparatively 
simple methods have been devised for identifying single chemical bodies present and 
thus furnish a means of ascertaining the origin of the substance under examination. 

PERCENTAGES OF THE ELEMENTS PRESENT IN BITUMI- 
NOUS SUBSTANCES 

Bituminous substances are composed of the following elements: carbon, hydro- 
gen, oxygen, sulphur, and nitrogen. It is comparatively simple by analytical 
methods to determine the mere percentages of the elements present. An expres- 
sion of the percentages of the elements present in a substance is termed its ulti- 
mate analysis, in contra-distinction to its exact chemical composition. The ultimate 
analysis will often furnish a clue as to its identity. 

The element nitrogen is rarely present in excess of 2 per cent of the non-mineral 
constituents. Mineral waxes are usually free from nitrogen. Petroleum, asphalt, 



CHEMISTRY OF BITUMINOUS SUBSTANCES 



43 



Oxygen, 
100 per cent 




40 50 60 

Line of zero carbon 



Fig. 11. — Trilinear Coordinates on an Equilateral Triangle. 



asphaltites and pyrobitumens contain amounts varying from a trace to 1.7 per 
cent of nitrogen. Tars and pitches contain from to 1 per cent of nitrogen. 

The percentage of sulphur in 
bituminous materials varies con- 
siderably. Ozokerite, parafEne 
wax, montan wax, coal tar, coal- 
tar pitch, pine tar, pine-tar pitch, 
hardwood tar, hardwood-tar pitch, 
and fatty-acid pitch are practi- 
cally free from sulphur. 

In petroleum, the sulphur 
varies from a trace to 5 per cent 
as a maximum. Mexican petro- 
leum contains between 3 and 5 
per cent. Trinidad and Cahfornia 
petroleums contain approximately 
i to 4 per cent. Mixed-base pe- 
troleums including the Mid-conti- 
nental and Texas oils contain from 
a trace to about 2^ per cent. 
Paraffinaceous petroleums contain 
merely a trace. Residual oils con- 
tain from a trace to 5 per cent. 
Residual asphalt, blown asphalt, 
sludge asphalt, native asphalts, asphaltites, asphaltic pyrobitumens, and non-asphaltic 




100% 10 
Fig. 12 



100% 



-Trilinear Coordinates on an Isosceles 
Triangle. 



44 



ASPHALTS AND ALLIED SUBSTANCES 



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ment of 



pyrobitumens contain from a trace 
to 10 per cent of sulphur. Tars and 
pitches derived from non-asphaltic 
pyrobitumens contain from a trace to 
1| per cent. 

As far as we can determine, the 
presence of nitrogen and sulphur vary 
according to no known laws and may 
therefore be regarded as adventitious. 
On the other hand, the percentages 
of carbon, hydrogen, and oxygen 
appear to follow well-defined laws, 
and may be used as criteria to differ- 
entiate between the various classes 
of bituminous materials. The in- 
vestigations of O. C. Ralston^ have 
done much to clear up this subject. 
Analyses are first calculated to a 
moisture-free, ash-free, nitrogen-free, 
and sulphur-free basis, so that the 
percentages of carbon, hydrogen, and 
oxygen will add up to 100 per cent. 
The results are then plotted on a 
special type of trilinear coordinates. 

To explain this we will first refer 
to the usual form of trilinear co- 
ordinates adapted to substances com- 
posed of the three elements carbon, 
hydrogen, and oxygen, illustrated in 
Fig. 11. It is more convenient, how- 
ever, to use an isosceles right-angle 
triangle as shown in Fig. 12. Since 
none of the bituminous substances 
contain more than 15 per cent of 
hydrogen, only the part of the tri- 
angle represented by the shaded 
section in the preceding illustration 
need be used. Fig. 13 shows the 
shaded portion of Fig. 12 drawn on 
an enlarged scale, on which are plotted 
the typical bituminous substances. 

The percentages of oxygen con- 
tained in the more important bitu- 
minous materials (calculated on the 
mineral-free basis) are shown in 
Table XXXV on page 483. With the 
exception of the non-asphaltic p3'^ro- 
bitumens, the percentage of oxygen 

Interior, Bureau of Mines, Wash., D. C. 



CHEMISTRY OF BITUMINOUS SUBSTANCES 45 

does not exceed 5. This is significant. The hydrogen, on the other hand, never exceeds 
15 per cent. In the paraffine series of hydrocarbons, the carbon is combined with 
as much hydrogen as possible, and this accordingly contains the largest percentage 
of hydrogen and the smallest percentage of carbon. The lowest member of this 
series CH4, a gas, contains 75 per cent of carbon and 25 per cent of hydrogen. 
The member C30H62 contains 85.31 per cent of carbon and 14.69 per cent of hydro- 
gen. In the olefine series CnH^n, the relation of carbon to hydrogen is constant, 
and figures: carbon 85.71 per cent and hydrogen 14.29 per cent. 

The greatest percentage of carbon found in any bituminous substance is in 
the case of anthracite coal, which runs as high as 98 per cent. The smallest per- 
centage is contained in certain peats, which run as low as 50 per cent. With the 
exception of the non-3,sphaltic pyrobitumens, carbon ranges from 85 to 95 per cent. 



CHAPTER IV 
GEOLOGY AND ORIGIN OF BITUMENS AND PYROBITUMENS 

Geology 

Age of the Geological Formations. The earth's crust has been divided 
into natural groups or strata in the order of their antiquity. There are 
five main divisions, which range in sequence as follows : 

1. Quarternary or Post-tertiary, representing the strata now in the 
, process of formation. 

2. Tertiary or Caenozoic, embracing the age of recent life. 

3. Secondary or Mesozoic, representing the less recent life. 

4. Primary or Paleozoic, representing the so-called " ancient life." 

5. Archaean or Azoic, representing the so-called lifeless strata. 

These divisions are recognized by the distinctive organic remains, 
fossils, minerals and other characteristics. They are classified into various 
" systems " as shown in Table XII on the opposite page. 

The systems form a chronological time-chart indicating the relative 
ages of the earth's strata. The systems are further sub-divided into groups 
which differ in different localities, but it will be unnecessary to consider 
their sub-classification here. 

Petroleum occurs in all of the geological systems from the Recent down 
to the Pre-Cambrian. Certain systems are richer than others, especially 
the Pliocene, Miocene, Oligocene, Eocene, Carboniferous, Upper Devonian 
and Lower Silurian (Ordovician) . Asphalts, asphaltites and non-asphaltic 
pyrobitumens are found in all the systems from the Pliocene to the Silurian. 
Mineral waxes are found largely in the Pliocene, Miocene, Oligocene, 
Eocene and Cretaceous. 

The non-asphaltic pyrobitumens do not occur in the older Paleo- 
zoic formations (i.e. the Silurian or Cambrian Systems). The Carbonifer- 
ous System contains the most valuable coal deposits; the Permian and 
Triassic Systems contain coals of inferior quality, and the coals found in 
the Jurassic, Cretaceous, Eocene and Oligocene Series are still more 
inferior in quality. Lignite occurs in the Oligocene, and Miocene Series, 
and peat in the Pliocene and Pleistocene. The Pre-Cambrian Series 
consists largely of crystalline, metamorphic rocks of volcanic and igneous 

46 



GEOLOGY AND ORIGIN OF BITUMENS 



47 



origin. The non-asphaltic pyrobitumens, as might be expected, do not 
occur in rocks of this character. Graphite, however, occurs in the Pre- 
Cambrian rocks, and may possibly have been derived from vegetable 
matter, although no signs of associated plant remains have been found in 
these rocks. 

TABLE XII 



Era. 

Quarternary or Post- 
tertiary 



Tertiary or Csenozoic . . 



Secondary or Mesozoic . 



System. 

{Historic 
Prehistoric 
Neolithic 
Pleistocene or Glacial 

Pliocene 

Miocene 

Oligocene 

Eocene 



Cretaceous. 



Primary or Paleozoic, 



Jurassic 

Triassic 
Permian 
Carboniferous 



Devonian. 



Silurian . 



Upper 

Middle 

Lower 

Upper 

Middle 

Lower 



Upper 
Lower 

Upper 
Middle 
Lower 



f Upper 



Cambrian. 



Lower (Ordovician) 

Upper 
Middle 
Lower 



Archaean or Azoic Pre-Cambrian 



The particular geological system is of value in enabling us to prospect 
and trace deposits of bitumens and pyrobitumens in any given locality. 

Character of the Associated Minerals. Bitumens and pyrobitumens, 
with but few exceptions, are found in sedimentary deposits of sand, sand- 
stone, limestone and sometimes in shale and clay. Rare occurrences have 
been reported in igneous rocks, but then only in very small quantities. 

Modes of Occurrence. Bitumens and pyrobitumens are found in 
nature in the following ways: 

1. Overflows: 

(a) Springs. 
(5) Lakes, 
(c) Seepages. 



48 ASPHALTS AND ALLIED SUBSTANCES 

2. Impregnating Rocks: 

(a) Subterranean pools or reservoirs. 
(6) Horizontal rock strata, 
(c) Vertical rock strata. 

3. Filling Veins: 

(a) Caused by vertical cleavage. 

(b) Caused by upturning. 

(c) Caused by sliding. 

(d) Formed by sedimentation. 

Springs. Petroleum and the liquid forms of asphalt only are found in springs 
(Fig. 14). These emanate from a fissure, crevice, or fault which permits the petro- 
leum or liquid asphalt to rise to the surface from some depth. Petroleum or 
asphalt springs have been reported in various parts of the world, but are rarely of 
commercial importance. 

Lakes. Asphalt only is sometimes found in lakes, which are in reality springs 
on a very large scale (Fig. 15). Some of our largest and most valuable deposits 
occur in this form, the best known being the lakes at Trinidad and Venezuela. 
It is probable that the asphalt is forced up from below in a liquid or semi-liquid 
condition by the pressure of the oil and gas underneath, which causes it to flow 
through a fissure or fault and spread over a large area at the surface. Lake 
asphalts are moderately soft where they emanate, but harden on exposure to the 
elements. 

Seepages. These occur in the case of petroleum or liquid asphalts, and usually 
from cliffs or mountains bearing impregnated rock. Either the pressure of the 
material itself or the heat of the sun causes a certain quantity, usually not very 
large, to flow out of the rock and run towards the lower level. (Fig. 16.) Seepages 
are often found where a rapidly flowing stream of water cuts its way through 
strata of rock impregnated with petroleum or asphalt. From a commercial stand- 
point, seepages of asphalt or petroleum are of little value. 

Subterranean Pools or Reservoirs. Practically all deposits of petroleum of any 
magnitude occur below the surface of the earth in subterranean "pools" or "reser- 
voirs." These consist of porous sand, sandstone, limestone (or dolomite) with a 
more or less impervious rock cover. The porous bed is exemplified by coarse-grained 
sandstone, conglomerate, or limestone. The limestone may have been dense as it 
existed originally, but rendered porous in the course of time by conversion into 
dolomite, with the consequent production of voids due to shrinkage, since dolomite 
occupies less space than the original limestone. The petroleum is carried in the 
interstices of the porous rock and prevented from volatilizing or escaping by an 
impervious cover known as the "cap-rock," usually composed of shale or a dense 
limestone. The main supplies of petroleum have been obtained from regions which 
have been comparatively undisturbed by terrestrial movements. In such cases the 
accumulation of petroleum underneath forms what is known as a "pool" or "res- 
ervoir " (Fig. 17). 

Impregnated Rock in Strata. Liquid to semi-liquid asphalts occur in this man- 
ner. Rocks impregnated with asphalt are produced in two ways, viz.: 

(1) By the gradual evaporation and hardening of an asphaltic petroleum due 



GEOLOGY AND ORIGIN OF BITUMENS 



49 



M- 5 


- ''" (M 


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:^=-.^^=F^T-rrrT 


i^rrTiT-, j=3:?T^?ih;^ 






100 200 Feet 




<:». 






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spring 
FIG. 14 



La ke 

FIG.15 




I ^ Miles 



Cap Rock (Shale) 
Wafen OIL das, Oi'l^ Wate"; 




Seepages 
FI0.I6 



Subteranean Pool or Reservoir 
FIO.17 



100 zoo Feet 
■ ■ I ■ ' 

Ledge Outcrop 




Angle 
of Dip ' 



lOO 200. Feet 



v^^m. 



^•■^^^a>•= ei^:■■-^•.^^.. 



ffi^^w 



rfi YV ]' V M ^ \ I I ^A- 




Impregnated Horizontal Strata 
FI6.18 



Impregnated Strata m. Thrust 
F1G.19 




Fault Fillinq caused bv Clearage Fault Filling caused by Upturning 

^ F1G.20 FIG. El 



100 zoo Feet 




\\\ \ I'rV-rf-TTTT 



Vein Fillinq caused by Sliding of Strata Veins formed by Sedimentation 






^ 



ri'\ T 



Pure Rock Alluvium Sand Sand Limestone Clay Shale 6rahit? 
Asphalt Asphalt Stone 



Figs. 14-23. 



50 ASPHALTS AND ALLIED SUBSTANCES 

perhaps to the disturbing or removal of the cap-rock, leaving the asphalt residue 
filling the interstices of the stratum carrying it. These are usually found in hori- 
zontal strata (Fig. 18). 

(2) By the liquid asphalt being forced upward under pressure, or drawn up- 
ward by capillarity from underlying strata into a porous rock layer above it. 
These are usually found in the region of a "thrust" or upturning of the earth's 
strata (Fig. 19). 

Filling Veins. The harder asphalts, asphaltites and asphaltic pyrobitumens are 
most commonly found filling fissures in a more or less vertical direction, caused 
by "faulting." In geology, a "fault" is a more or less vertical crack in the earth's 
surface brought about by the contraction and uneven settling of the strata. This 
is occasioned by a greater movement in the rock on one side of the fault's plane 
than on the other, as illustrated in Fig. 20, or by the upturning of a section of 
the earth's crust as shown in Fig. 21. Faults allow the hquid or molten asphalt 
to force its way up from underneath and fill the crevice. As will be described 
later, after the asphalt hardens in the fault, it might in time become metamor- 
phosized and converted into an asphaltite or asphaltic pyrobitumen. Non-asphaltic 
pyrobitumens are never found in faults, probably because they are incapable of 
softening or melting under the action of heat, either in their original state or 
afterwards. 

Sometimes we find the harder asphalts, asphaltities and asphaltic pyrobitumens 
filling a more or less horizontal fissure or cleavage crack, brought about by the 
sliding of two strata, one upon the other. The opening between the strata becomes 
filled with the liquid or melted asphalt, forced up under pressure through a crevice 
from below, which then hardens, giving rise to a horizontal vein as shown in Fig. 22. 

Horizontal veins are sometimes derived from prehistoric asphalt "lakes," per- 
haps similar to our present Trinidad or Venezuela lakes. In time, these harden, 
and become submerged in water, due perhaps to a movement in the level of the 
earth's crust. The water permits the sedimentation of mineral matter, so that the 
lake is gradually converted into a horizontal vein. If the liquid asphalt again 
breaks through a fault or fissure, it will form a superimposed vein, or perhaps a 
series of such veins between sediments, as shown in Fig. 23. 

In the case of non-asphaltic pyrobitumens, the veins were unquestionably formed 
by a process of sedimentation. The vegetation from which these were derived, 
originally grew in swampy or marshy localities, presumably about the mouths of 
rivers. As the vegetation died, it became covered with sediments of sand or clay 
carried down by the water, or by calcium carbonate precipitated from the water, 
which in turn formed soil for subsequent growths. These gave rise to the future 
veins of non-asphaltic pyrobitumens, which are similar structurally to the pre- 
ceding (Fig. 23). 



Movement of Bitumens in the Earth's Strata. It is a singular fact 
that petroleum, mineral waxes, asphalts and asphaltites are not always 
found in the same locaUty in which they originated. They have the power 
of migrating from place to place, and many deposits are still in the proc- 
ess of migration. A " primary deposit " is one in which the bituminous 
material is still associated with the same rocks in which it originated. 
A " secondary deposit " is one to which the material has subsequently 



GEOLOGY AND ORIGIN OF BITUMENS 51 

migrated. Bitumens usually migrate while in a liquid or melted con- 
dition, although in certain rare instances the migration has been induced 
by the action of flowing water while the bitumen is in the sohd state. 

The main causes for the movement of native bituminous substances in the earth's 
surface are as follows: 

(1) Hydrostatic Pressure. This is largely responsible for the accumulation of 
petroleum in pools or reservoirs. At some distance below the earth's surface there 
is an accumulation of ground water, the level of which varies in different localities 
and during different seasons. The petroleum, being lighter than the water, floats 
on its surface. As the level of the ground water varies, it will move the petroleum 
about through interstices in the rock. The water tends to push the oil ahead of 
it, and this will account for the accumulation of the petroleum in the form of 
pools or reservoirs underneath a cap of a dense and non-porous strata through which 
it cannot permeate. . This will also explain why there is often an accumulation of 
petroleum in the ground near the top of a hill or mountain. Oil and gas are often 
encountered under pressure, due to the hydrostatic head of water. 

Hydrostatic pressure may also cause the migration of sohd asphalts, as for 
example in the case of the Dead Sea, where masses become detached from the bottom and 
are caused to float upward by the higher gravity of the water, due to the large 
percentage of salt dissolved in it. 

(2) Gas Pressure. It is probable that the action of the heat or other forces 
below the surface of the earth, tend to partially vaporize certain bitumens, so that 
the resulting gas will force them into the overlying strata near the surface. In 
other instances the effect of faulting, crumpling, upturning, erosion and other move- 
ments of the earth's strata exposes the oil- or asphalt-bearing formations, and enables 
the gas pressure to force them to the surface. Natural gas exists under great 
pressure in certain localities. Many gas wells in the Baku and Pennsylvania 
fields have registered a pressure of 600 to 800 lb., and even as high as 1000 lb. 
per square inch. This may be accounted for by the fact that as the gas is 
constantly being generated, it accumulates inside of the earth's surface and has no 
access to escape owdng to the density of the strata above. 

(3) Capillarity. This force takes place in dry porous rocks and acts on per- 
manently liquid bitumens, or bitumens solid at ordinary temperatures but trans- 
formed to the melted state by the action of heat. Under these conditions the 
bitumen will soak into the pores of the rock or sand and gradually fill the inter- 
stices. Capillarity is a very much stronger force than gravity, although other 
forces, such as the action of heat (see under 5) may be partly responsible. The 
finer the pores in the rock, the greater the capillary force. Rocks saturated with 
moisture tend to resist the action of capillarity, which is most effective in the 
dry state. 

(4) Gravitation. The natural weight of the overlying strata caused by gravi- 
tation sets up a pressure where there are accumulations of petroleum or other 
forms of liquid bitumen underneath, and if a fissure or fault occurs in the earth's 
crust, the bitumen being softer than the surrounding rock, will be forced to the 
surface. Gravitation is therefore selective in its action and by exerting a greater 
pull on the heavier bodies will tend to force the lighter ones upward. Under other 
circumstances, where the substances are not confined, the result of gravitation is 
to cause the petroleum or liquid asphalt to ooze from the over-lying rock matrix 
in the form of "seepages." 



52 ASPHALTS AND ALLIED SUBSTANCES 

(5) Effect of Heat. Heat is also a large factor in causing the migration of 
bituminous substances. Its effect is variable. Under certain circumstances it will 
convert the solid bitumens into a liquid state and thus enable them to be acted upon 
by the various forces considered previously. Under other conditions, heat in the 
interior of the earth will vaporize the bitumens such as petroleum and force them 
upward. Again, if the heat is sufficiently intense, it is apt to cause the bitumens 
to undergo destructive distillation, the distillate condensing in the upper and cooler 
layers. 

Origin and Metamorphosis of Bitumens and Asphaltic 
Pyrobitumens 

Probable Origin of Bitumens and Asphaltic Pyrobitumens. Although 
much has been written on this subject, no generally acceptable conclu- 
sions have been reached. The discussion has in the main centered about 
the origin of petroleum, as this is conceded to be the mother substance, 
.from which the other bitumens and pyrobitumens are supposed to be 
produced by a process of metamorphosis. The theories have been divided 
into two classes, namely, the inorganic and the organic. We will con- 
sider these in greater detail. 

Inorganic Theories. It is contended that the interior of the earth 
contains free alkaline metals, presumably in a melted condition. These 
at high temperatures would react with carbon dioxide forming acetylides 
which in turn produce hydrocarbons of the acetylene series upon coming 
in contact with water. The acetylenes being unsaturated would have 
a tendency to combine with free hydrogen and give rise to the olefine 
and paraffine series. 

Still another theory based on similar lines, assumes the presence 
of metal carbides, including iron carbide, some distance below the sur- 
face of the earth. These are supposed to decompose on coming in con- 
tact with water and produce hydrocarbons, which upon condensing 
in the cooler upper strata give rise to petroleum. This, however, is 
mere speculation, for no iron carbide has ever been found. The occur- 
rence of hydrocarbon gases in volcanic emanations has been cited to 
substantiate this theory. 

The cosmical hypothesis is based upon the assumption that hydro- 
carbons were present in the atmosphere which originally surrounded 
the earth, after it had been thrown off by the sun. These hydrocarbons 
are claimed to have been formed by a direct combination of the elements 
carbon and hydrogen in the cosmic mass. As the earth cooled, the 
hydrocarbons condensed in the earth's crust, giving rise to deposits similar 
to those existing to-day. This theory has also been connected with the 
carbide theories, upon the assumption that at the high temperatures to 



GEOLOGY AND ORIGIN OF BITUMENS 53 

which the gases must have been subjected at the time they were thrown 
off by the sun, and before they condensed, the first compounds formed 
were carbides, silicides, nitrides, and the Hke. As oxidation would not 
commence until some time later, it is assumed that these carbides would 
remain locked up in the interior of the earth for geologic ages, and 
then gradually give rise to hydrocarbons upon being decomposed through 
the agency of water. 

Vegetable Theories. It has long been known that certain hydro- 
carbons result during the decay of vegetation. The hydrocarbon methane 
(CH4), otherwise known as *' marsh gas " is produced in this manner, 
but only in comparatively small amounts. Similarly methane has been 
detected in the gases resulting during the decay of seaweed. 

It has been shown by others that under certain conditions hydro- 
carbons may be produced artificially by the fermentation and decay of 
certain forms of cellulose, including woody fibre. Still other scientists 
maintain that petroleum is produced by microscopic plants known as 
diatoms, which occur abundantly in peat beds, and certain bogs. These 
organism-s are found to contain minute globules of oily m.atter distributed 
in the plasma, and moreover, a waxy substance resembling ozokerite may 
be extracted by solvents from the diatomaceous peat. It is contended 
that this oil will in time and under pressure become converted into liquid 
petroleum, and at higher temperatures and pressures possibly into asphalt. 
In support of this hypothesis a bed of peat has been described near 
Stettin, Germ^any, consisting largely of diatoms and from which hydro- 
carbons have been extracted in quantities up to 4 per cent. 

Another theory based on similar lines, infers that petroleum is derived 
from a slimy substance rich in organic matter known as '' sapropel," 
composed largely of algae, which accumulates at the bottom of stagnant 
waters. This sHme becomes covered with sediments which through the 
agency time and pressure, is assumed to give rise to petroleum, and 
under certain conditions, to asphalt. 

In a similar manner, bitumens are claimed to have been formed from 
deposits of vegetable matter, including various marine plants, seaweeds, 
etc., which accumulate at the bottom of the ocean. Just as the non- 
asphaltic pyrobitumens (e.g., coal) are produced by the decomposition 
of terrestrial vegetation, it is contended that bitumens have arisen from 
the decay of marine plants. This theory has a number of adherents. 
The optical activity of certain petroleums has been cited to substantiate 
the contention, since oils derived from organic matter can only possess 
this property. It has been proven that hydrocarbons produced from 
inorganic substances, such as metal carbides, do not exhibit optical activity. 



54 ASPHALTS AND ALLIED SUBSTANCES 

Still another theory, advocating the vegetable origin of petroleum,, 
assumes its derivation from peat, lignite or coal, which have been sub- 
jected to a sufficiently high temperature to undergo a process of destruc- 
tive distillation, resulting in the production of liquid and gaseous hydro- 
carbons. This is supposed to have occurred at great depths below the 
earth's surface and the hydrocarbons condensed in upper layers. 

The asphaltic pyrobituminous shales are similarly claimed to have 
generated petroleum under the action of heat, based on the well-known 
fact that when these shales are distilled comm.ercially, petroleum-like 
oils are produced. It is contended that the shales themselves were 
derived from gelatinous algse whose remains are still recognizable in 
certain of them with the aid of a microscope. 

Animal Theories. In a similar manner, petroleum and asphalt are sup- 
posed to have been produced from the accumulation of animal matter 
at the bottom of the ocean, which in time decomposed into hydro- 
carbons. The presence of nitrogen in all form.s of bitumen, is cited in 
substantiation of its production from albuminoid matter. The remains of 
molluscs and fish are present in certain asphaltic pyrobituminous shales, 
including the Albert series of New Brunswick, and in many rocks carry- 
ing petroleum and asphalt. Deposits of the latter have been reported 
in Galicia, Wyoming, and are particularly noticeable in the case of oil 
and asphalt deposits in Uvalde County, Texas, and southeastern Cali- 
fornia. In Egypt, shells are also found filled with bitumen. Others 
contend that the living cells are in some manner absorbed into the pores 
of coral reefs, and that these in time result in the formation of bituminous 
limestone. 

Substances closely resembling petroleum and bitumens have been 
produced artificially by subjecting fish albumin to heat, under pressure. 
Animal fats have similarly been converted into hydrocarbons boiling 
below 300° C. (See p. 330.) The conversion of fats and albuminous 
substances into petroleum is said to depend upon three factors, namely, 
pressure, temperature and time. The variations in the composition 
of petroleum found in different localities, is accounted for by variations 
in one or more of these factors. 

In conclusion it might be stated that probably all three theories 
embody certain elements of truth. The cosmical hypothesis is sustained 
by the fact that hydrocarbons have often been found in meteorites (see 
p; 79). The inorganic theory is borne out by the fact that hydrocarbons 
occur in volcanic emanations. The vegetable and animal theories in turn 
are supported by the presence of bitumens and pyrobitumens in rocks of 
sedimentary character, often carrying vegetable and animal fossil remains. 



GEOLOCY AND ORIGIN OF BITUMENS 65 

It is highly probable, therefore, that bitumens owe their origin to two or 
more of the theories which have been discussed, which would account 
for their varying chemical composition and physical characteristics. 

Metamorphosis of Mineral Waxes, Asphalts, Asphaltites and Asphaltic- 
Pyrobitumens from Petroleum. Although there seems to be a wide 
difference of opinion regarding the origin of petroleum, authorities are 
pretty well agreed that petroleum when once formed, is gradually con- 
verted into the other types of bitumen and pyrobitumens, under the 
influence of time, heat and pressure. This process of transformation 
is known as " metamorphosis." 

It is contended that mineral matter is a finely divided form, as for 
example '^ colloidal " clay, hastens this transform^ation by acting as a 
catalyzer. This theory is advanced by Clifford Richardson.^ In study- 
ing the well-known Trinidad asphalt lake deposit, Richardson concludes 
that an asphaltic petroleum existing at a considerable depth is converted 
into a more solid form of bitumen, namely asphalt, upon being thoroughly 
emulsified with colloidal clay, sand and water through the medium of 
natural gas at a high pressure. The elements of time and temperature 
are equally important factors. 

During the m.etam.orphosis, hydrogen is gradually eliminated, the 
hydrocarbons becoming enriched in carbon, and from a chemical stand- 
point more complex structurally. The changes brought about during 
this process may be regarded as a form of polymerization, in which the 
hydrocarbon molecules become rearranged into more complex molecules 
of higher molecular weight. 

The simplest hydrocarbons are present in petroleum. Those in 
mineral waxes are somewhat more complex, and both the structural 
complexity and the molecular weight increase in the case of asphalts 
and the asphaltic pyrobitumens. There are no sharp lines of demarcation 
between the various types of bitumens or asphaltic pyrobitumens. Each 
class gradually merges into another, and specimens will often be found 
on the border line, so that it is difficult to decide to which class they 
actually belong. (See p. 127.) 

From this view-point we may regard petroleums as passing in gradual 
stages, under the influence of time, heat, pressure and catalyzers into 
the soft native asphalts, which in turn pass into harder native asphalts, 
then into asphaltites and finally into the asphaltic pyrobitumens and 
asphaltic pyrobituminous shales.^ 

1 J. Ind. Eng. Chem., 8, 3, and 493; 1916, Met. Chem. Eng., 16, 3, 1917; St. Paul {Minn.) Eng. 
Soc, May, 1917; J. Soc. Chem. Ind., 37, 59A, 1918. 

-See also C. F. Mabery, "The Relations in Composition of the Different Forms of Natural 
Bitumens," J. Am. Chem. Soc, 39, 2015, 1917. 



56 ASPHALTS AND ALLIED SUBSTANCES 

It is highly probable that all deposits of asphalt are produced by 
metamorphosis from asphaltic petroleum. Similarly it seems likely that all 
deposits of mineral wax, such as ozokerite, etc., result from the meta- 
morphosis of paraffinaceous petroleum. 

The transformation manifests itself from a physical standpoint by: 

(1) An increase in specific gravity. 

(2) An increase in fusing-point. 

(3) An increase in hardness. 

(4) An increase in the percentage of fixed carbon. 

(5) A decrease in the percentage of soluble in naphtha. 

(6) A decrease in the percentage of volatile matter. 

(7) An increase in the flash- and burning-points. 

Although certain members are soluble in carbon disulphide, yet as the 
metamorphosis progresses, the solubility decreases, and this is particularly 
noticeable in the case of asphaltic pyrobitumens. 

Elaterite, wurtzilite, albertite, impsonite and the asphaltic pyro- 
bituminous shales represent the final stages in the metamorphosis of 
petroleum. The first four are comparatively free from mineral matter. 
If the latter predominates, the product is known as an asphaltic pyro- 
bituminous shale. The non-mineral matter contained in these shales 
has the same general characteristics as elaterite, wurtzilite, albertite 
or impsonite, depending upon how far the metamorphosis has progressed. 

In this connection it is interesting to note that on distiUing non-asphaltic or 
mixed-base petroleums, so that the residue in the still reaches a temperature 
between 600 and 800° F., a form of polymerization takes place whereby asphalt- 
like substances are produced. In other words, the percentage of asphalt in the 
petroleum is increased under these conditions (p. 296). There is a critical tem- 
perature which favors the production of these asphalt-like bodies, known in petro- 
leum refining as the "asphalt-forming temperature." If this temperature is in- 
creased, "cracking" takes place, in which the asphalt is destructively distilled and 
decomposed into simpler molecules. 

The asphaltic pyrobitumens behave differently. When heated to between 600 
and 800° F., they undergo "cracking." This is in reahty a form of depolymeriza- 
tion in which complex molecules are broken down into simpler ones. As a result, 
the original substance, which is practically insoluble in organic solvents, increases 
materially in solubility. Elaterite and wurtzilite depolymerize and become com- 
pletely soluble in benzol and carbon disulphide. Albertite is more difficult to depolym- 
erize than elaterite or wurtzilite, requiring a higher temperature and an increased 
time of treatment. On the other hand, impsonite depolymerizes only slightly 
under these conditions. If heated to higher temperatures, the asphaltic pyrobitu- 
mens suffer destructive distillation, leaving a residue of coke. The depolymeriza- 
tion is similar to the action which takes place on melting fossil resins, such as 
copal, amber, etc., in manufacturing varnish. 



GEOLOGY AND ORIGIN OF BITUMENS 



57' 



An interesting series of tests has been made in connection with oil shales, 
as shown in the following table: 



TABLE XIII 





Soluble in Benzol. 




Before 
Heating, 
Per Cent. 


Temperature. 
Deg. C. 


Duration. 


After 
Heating, 
Per Cent.* 


Posidononxya shale from 
Reutlingen 


0.6 1 

f 
0.85 \ 

[ 

... { 
- { 

1.4 


250 
300 

400 

300 
350 
350 

250 
250 

300 
300 

400 
400 
400 
400 


24 hrs. 

Additional 24 hrs. 
Additional 24 hrs. 

ihr. 

Additional hour 
Additional 24 hrs. 

2 days 
Additional 8 days 

2 days 
Additional 8 days 

1 hour 

Additional 2 hrs. 
Additional 2 hrs. 
Additional 2 hrs. 


0.34 

3.24 \ 3.58 


Menilite shale from Strzytki, 
East Galicia 


0.00 ^ 

1.21 

70 [-2.31 


Shale from N. S. Wales. Aust. . . 
Shale from N. S. Wales, Aust. . . 

Shale from N. S. Wales, Aust . . . 


0.40 , 

Vs } 3- 

4.9 
0.0 ^ 



* Percentage calculated on the basis of the insoluble residue before heating. 

The following tables will give an approximate idea of the natural metamor- 
phosis of bitumens and pyrobitumens, one from another, likewise their behavior 
towards heat applied artificially. 



Non-asphaltic Petroleum 

i 

Mineral Waxes 



TABLE XIV 

Petroleum 



Mixed-base and Asphaltic Petroleums 
I 

Asphalts 



Pure and 
Fairly Pure 

1 

Asphaltites 

i 



Impure 
(Rock Asphalts) 

i 

(Impure Asphaltites) 

i 



Asphaltic Pyrobitumens Shales, Asphaltic Pyrobituminous 



58 



ASPHALTS AND ALLIED SUBSTANCES 



TABLE XIY— Continued 
Cellulose (Woody Fiber) 



Vegetable Growths in Bogs, Swamps, etc. 

i 

Feat 



Trees, etc. 



Impure (with IMineral Matter) 

i 

Lignite Shales 

^ i 

Coal Shales 



Pure 

i 

Lignite 

i 

Bituminous Coal 

i 

Anthracite Coal 

i 

Graphite 



TABLE XV.— BEHAVIOR ON SUBJECTING TO HEAT 



> 


Heated 


Heated 


Heated 


Heated 




under 300° C. 


300-450° C. 


450-700° C. 


700-1500° C. 


Non-asphaltic pe- 


Distil, and the 


Residues depoly- 








residues fuse 
Distil and the 


mcrize slightly. 
Residues polymer- 






Mixed base and as- 


' 




phaltic petroleums 


residues fuse 


ize, forming as- 






Mineral waxes 


Small amount dis- 
tils with slight de- 
composition, and 
the residues fuse 

Fuse 

Infusible and in- 


phalt-like bodies 
Depolymerize and 
distil 

Distil more or less 
Depolymerize and 


Depolymerize, 
yielding as dis- 
tillate mostly 
> open - chain 
hydrocarbons 
and a residue 
of coke 




Asphalts and As- 

phaltites 
Asphaltic pyrobitu- 




mens 


soluble 


become more 
soluble 






Non-asphaltic pyro- 


Infusible 


Unaffected 


Depolymerize 


Depolymerize, 


bitumens 






slightly and dis- 
til 


yielding as dis- 
tillate, mostly 
cyclic hydrocar- 
bons and a resi- 
due of coke 



Origin and Metamorphosis of Non-Asphaltic Pyrobitumens 



The origin of non-asphaltic pyrobitumens has been definitely established. 
The associated fossil remains clearly prove that these have been derived 
from vegetable matter containing cellulose, a carbohydrate having the 
empirical formula CeHioOs. 

The decomposition of cellulose when the air is partly or wholly excluded, as 
would be the case when buried in the ground, results in the loss of carbon dioxide, 



GEOLOGY AND ORIGIN OF BITUMENS 59 

methane, and water. In this manner, cellulose ultimately yields a series of prod- 
ucts grouped under the heading of non-asphaltic pyrobitumens. The conditions 
favorable to their production seem to be the growth of vegetable substances about 
the mouths of rivers, combined with a change in water-level. The sediment carried 
down by the river, formed beds of sand or clay which sealed the vegetation in 
between the strata. In this manner the vegetable matter was protected from 
atmospheric oxidation and at the same time probably subjected to fermentative 
heat, also to a gradually increasing pressure, as successive layers accumulated. 
The vegetation doubtlessly embraced many different kinds, including trees, ferns, 
grasses, mosses, and the like. Fossil ferns are stiU clearly evident in coal beds. 
In other cases carbonized trees, roots and fibrous tissue are recognizable, and in 
stiU others, the resins originally present in the wood are found intact. Amber 
and fossil copal often occur in peat, and large masses of resin have been identified 
in beds of lignite and bituminous coal. 

Peat represents the first stage in the metamorphosis of coal from vegetable 
matter, and occurs in bogs or other swampy places. Very often on the surface of 
a bog or swamp we see the still living and growing plants. A little below, we find 
their decayed remains, and &till deeper, a black glutinous substance saturated with 
moisture, known as "peat." 

The exact nature of the changes which take place in the transformation of 
vegetable matter into peat is not clearly understood. The ultimate analysis shows 
that the percentages of hydrogen and oxygen have diminished, and carbon corre- 
spondingly increased. In the most recent deposits, peat is loosely compacted, but 
as it accumulates under the sediments, it becomes compressed. A bed which was 
possibly once a foot thick might shrink to several inches. In all probability the 
pressure developed by the superimposed layers, aids in the transformation of peat 
into coal (see p. 198). 

Lignite or browncoal is intermediate between peat and bituminous coal. The 
most recent deposits approach peat in composition, and the oldest merge into 
bituminous coal. Lignite contains a larger percentage of carbon and smaller per- 
centages of hydrogen and oxygen than peat. 

According to Clarke,^ the Ugnites are grouped into six classes, viz.: 

(1) True lignite, in which the ligneous structure is more or less perfectly pre- 
served. 

(2) Earthy browncoal, which has an earthy structure, and a dull lustre, often 
accompanied by mineral resins or wax-like hydrocarbons, ^ which may be extracted 
by means of carbon disulphide or benzol. 

(3) Common browncoal, which is a compacted form of lignite. 

(4) Pitch coal having a compact structure and is so named on account of its 
peculiar pitch-like lustre. 

(5) Glance coal, which is a very hard and compact form of lignite, closely 
resembhng bituminous coal. 



i"The Data of Geochemistry," Bulletin No. 330, U. S. Geological Survey, Wash., D. C., 1908. 

2 The associated resins or waxes, or asphalts, as they are termed by some, have been described 
under various names, including: Anthracoxenite, Bombiccite, Branchite, Butyrellite, Dinite, 
Dopplerite, Duxite, Dysodile, Euosmite, Fichtelite, Geomyricite, Hartine, Hartite, Hofmannite, 
lonite, KoHachite, Leucopetrin, Leucopetrite, Melanchyme, Mellite, Middletonite, Muckite, Neu- 
doriite, Neft-Gil, Phytocollite, Pianzite, Pyroretin, Refikite, Retinasphaltum, Retinite, Rochlederite, 
Schleretinite, Sieburgite, Trinkerite, Walchowite, Wheelerite, etc. 



60 ASPHALTS AND ALLIED SUBSTANCES 

(6) Jet, representing an extremely hard variety of lignite, claimed to have been 
derived from coniferous woods. 

Cannel coal is in reality a subclass of bituminous coal, rich in volatile matter. 
It is supposed to have been derived from spores, spore cases, and resinous or waxy 
products of plants. The absence of woody material gives cannel coal a uniform 
texture and grain not present in other coals, so that it breaks with a conchoidal 
fracture, and a splinter ignites in contact with a lighted match, burning like a 
candle, whence it derives its name. G. H. Ashely^ classifies it as follows: 

(1) Subcannel coal: 

(a) Brown subcannel, of browncoal or lignite rank. 
(6) Black subcannel, of subbituminous rank. 

(2) Cannel coal, of bituminous rank: 

(a) Boghead cannel (fuel ratio ^ less than 0.5). 

(6) Typical cannel (fuel ratio ^ between 0.5 and 1). 

(c) Lean cannel or semicannel (fuel ratio ^ more than 1). 

' (3) Canneloid or semibituminous coal. 

Bituminous coal falls between lignite and anthracite coal. It is often a mat- 
ter of difficulty to determine where the lignites stop and the bituminous coals 
begin; similarly, the line of demarcation between bituminous and anthracite coals 
is not very distinct. Bituminous coals contain a larger percentage of carbon and 
smaller percentages of hydrogen and oxygen than lignite. The name "bituminous 
coal" is derived from the fact that this coal apparently softens and undergoes 
fusion at a temperature somewhat below that of actual combustion. The term, 
however, is a misnomer. The softening which takes place marks the point at 
which destructive distillation commences, accompanied by the formation of gaseous 
hydrocarbons. ''Bitumen" does not acutally exist in bituminous coal, which is 
easily proven by the fact that solvents for bitumen such as carbon disulphide 
have no appreciable effect upon it. Bituminous coals contain a substantial portion 
of volatile matter, which causes them to burn more rapidly than anthracite, and 
with a larger amount of flame. The so-called "coking coal" is a class of bitu- 
minous coal, used in the manufacture of coke. 

Anthracite coal represents the final stage in the transformation of vegetable 
matter into a non-crystalline form. It contains definite proportions of hydrogen 
and oxygen. Certain forms of anthracite approach gr&phite in their composition. 
Graphite on the other hand is a crystallized mineral composed entirely of carbon, 
and which is supposed to represent the final stage in the metamorphosis of coal. 
The mode of occurrence and microscopic structure of graphite deposits correspond 
closely with those of coal, giving rise to the behef that both were derived from a 
common source. 

The following table shows the maximum, minimum, and average percentages 
of carbon, hydrogen, oxygen, and nitrogen in wood, peat, lignite, bituminous coal, 
anthracite coal and graphite, calculated on the water-, ash-, and sulphur-free bases: 

1" Cannel Coals in the United States," U. S. Geological Survey, Bull, in preparation. 
2 The quotient ot the fixed carbon divided by the volatile matter. 



GEOLOGY AND ORIGIN OF BITUMENS 

TABLE XVI 



61 





Carbon, 
Per Cent. 


Htdrogen, 
Per Cent. 


Ox-. GEN, 

Per Cent. 


Nitrogen, 
Per Cent. 




Min. 


Max, 


Aver. 


Min. 


Max. 


Aver. 


Min. 


Max. 


Aver. 


Min. 


Max. 


Aver. 


Wood 

Peat 

Lignite 


40 
50 
65 
80 
90 
100 


50 
65 
80 
90 
95 


49.65 
55.44 
72.95 
84.24 
93.50 
100.00 


5\ 

5 

41 

4 

2 


7i 

7 

6^ 

6 

5 


6.23 
6.28 
5.24 
5.05 
2.81 


42 

26 

15 

3 

1 


50 
44 
28 
18 
5 


43.20 

35.56 

20.50 

8.69 

2.72 


1 
1 

1 


3 
3 
2 
2 
2 


0.92 
1.72 
1 31 


Bituminous Coal 
Anthracite Coal. 
Graphite 


1.52 
0.97 



A steady decreases in the percentages of hydrogen and oxygen thus becomes 
apparent, and especially if the average percentages are recalculated on the basis 
of 100 parts by weight of carbon, as shown in the following table: 





TABLE 


XVII 








Carbon. 


Hydrogen. 


Oxygen. 


Nitrogen. 


Wood 


100 
100 
100 
100 
100 
100 


12.5 

11.3 

7.2 

6.6 

3.0 


87.0 
64.1 
28.1 
10.3 
2.9 
.... 


1 8 


Peat 


3.1 


Lignite 


1.8 




1.8 




1.3 











It will be observed that the progressive decrease in the proportion of oxygen 
is greater than is the case with hydrogen. In cellulose CeHioOs, these two ele- 
ments exist in exactly the proportions required to form water (H2O), namely 
1:8. In wood, the hydrogen is slightly in excess of that ratio, and the excess 
steadily increases until in anthracite it is proportionately very large. In the former, 
the ratio is nearly 1 : 7, whereas in the latter it is roughly 1:1. 

These facts are significant, and enable us to arrive at a basis for properly 
classifying the various non-asphaltic pyrobitumens. 



CHAPTER V 

ANNUAL PRODUCTION OF ASPHALTS, ASPHALTITES AND 
ASPHALTIC PYROBITUMENS 

World Production. Deposits of natural asphalts have been discovered in all 
parts of the world. Table XVIII, compiled bj^ the Department of Interior of the 
U. S. Geological Survey, shows the total production of all forms of native asphalts 
(including pure and rock asphalts), asphaltites and asphaltic pyrobitumens, from 
1906 to 1916 inclusive, as far as reliable statistics are available.^ 

Trinidad produces the largest quantity of native asphalt, Italy comes next, 
then Germany, United States and Venezuela. In the above statistics the ouput 
of petroleum asphalt is not included. 

Production in United States. The annual production of native asphalts, asphal- 
tites, asphaltic pyrobitumens, and petroleum asphalt in the United States is shown 
in the Table XIX. 

From this it will be observed where as the production of native asphalts remained 
fairly constant from the years 1897 to 1916, the production of petroleum asphalt 
has been steadily increasing. During the last few years, the advent of petroleum 
asphalt manufactured from Mexican crude has become quite a factor. 

The production of gilsonite and grahamite have not varied greatly during the 
last eight or nine years. Wurtzilite is not an important factor in the asphalt 
industry. 

The figures in the preceding table, under the head of "Native Asphalts," com- 
prise rock asphalts, including asphaltic sandstones and limestones, together with a 
small proportion of pure native asphalt. The production of the last named is 
relatively unimportant, and has not therefore been segregated. 

The accompanying diagram (Fig. 24) shows the production of native asphalts 
(including rock and pure asphalts), asphaltites, asphaltic pyrobitumens and manu- 
factured asphalts (petroleum asphalts made from domestic and Mexican crudes), 
together with the imports of crude asphalts into the United States from the years 
1880 to 1916 inclusive. 

In 1916, the production of petroleum asphalt from domestic crudes amounted 
to 688,334 short tons, including 404,009 tons of residual oil used either for road 
sprinkling or as a flux for softening harder asphalts, and 284,325 short tons of 
residual asphalts. These figures show a decrease of 13,800 tons in the production 
of road oils and fluxes, and an increase of 37,681 tons in the output of residual 
asphalt, as compared with 1915. 

In 1916 the output of petroleum asphalts from Mexican crudes amounted to 
572,387 short tons, including 295,682 tons of road oils and fluxes, and 276,705 tons 

1 "Asphalt, Related Bitumens, and Bituminous Rock in 1916," by John D. Northrup. Wash., 
D. C. Sept. 22, 1917. 

62 



ANNUAL PRODUCTION OF ASPHALTS 



63 



TABLE XVIII 





United States. 


Trinidad. a 


Germany. 


C.BA. 


Year. 


Quantity 

(short 
tons). 


Value. 


Quantity 

(short 
tons). 


Value. 


Quantity 

(short 
tons). 


Value. 


Quantity 

(short 
tons). 


Value. 


1906 


73.062 
85,913 
78,565 
99,061 
98,893 
87,074 
95,166 
92,604 
79,888 
75,751 
98,477 


8674,934 
928,381 
517,485 
572,846 
854,234 
817,250 
865,225 
750,713 
642,123 
526,490 
923,281 


150,373 

171,271 

143,552 

159,416 

157,120 

6201,284 

6212,236 

6257,635 

6163,076 

6152,349 

6146,831 


$832,964 
832,274 
403,023 
459,446 
421,419 

c603,800 

c742,800 
cl,030,540 

c789,450 
736,760 

c698,47c 


129,388 
139,567 
98,088 
85,446 
89,491 
90,256 
105,950 


$268,631 
264,494 
188,334 
176,897 
152,565 
154,938 
200,743 


5,717 

5,571 

6,875 

11,900 

2,320 

3,638 

17,260 

61,749 

6969 

6486 

d327 


$26 605 


1907 


37,594 


1908 


31,574 


1909 

1910 


48,246 
13,685 


1911 


21,928 


1912 

1913 


87,500 
30,935 


1914 






19,491 


1915 






11,247 


1916 






7,61J 













France. 


Italy. 


Spain. 


Japan. 


Year. 


Quantity 

(short 
tons) . 


Value. 


Quantity 
(short 
tons). 


Value. 


Quantity 

(short 
tons) . 


Value. 


Quantity 

(short 
tons) . 


Value. 


1906 

1907 


216,405 
195,136 
188,616 
186,238 
187,085 


$345,599 
330,065 
264,188 
269,161 
277,210 


144,802 
178,127 
148,433 
123,361 
179,261 
207,926 
200,560 
188,601 
132,114 
52,53: 


$349,926 

442,014 
368,306 
305,159 
452,911 
591,550 
581,383 
521,398 
400,164 
184,621 


8,587 
9,057 
13,635 
5,822 
7,072 
/ 4,124 
5,938 
6 153 
6,355 
4,98S 


$17,130 
16,001 
24,084 
10,282 
18,308 
8,754 
13,003 
13,402 
13,847 
10,706 


43 
644 
2,650 
4,614 
526 
1,389 
3,199 
2,491 
2,211 


$3,572 
5,436 


1908 

1909 


25,564 
45,205 


1910 

1911 


29,004 
13 728 


1912 






32,518 


1913 






27,242 
25 836 


1914 






1915 





















Austria-Hungary. 


RUS.SIA. 


Venezuela. 


Mexico. 


Year. 


Quantity 
(short 
tons). 


Value. 


Quantity 
(short 
tons). 


Value. 


Quantity 

(short 
tor.s). 


Value. 


Quantity 
(short 
tons). 


Value. 


1906 


10,633 
11,335 
12,239 
11,179 
9,070 
/i 8,312 
h 11,439 


8778,781 
727,892 
768,162 
663,246 
702,022 
652,603 
664,778 


& 12,517 
g 14,116 
g 24,961 
A 2,665 
h 27,544 


8110,294 

101,705 

491,302 

4,599 

176,518 


6 24,783 
6 42,153 
6 35,324 
6 41,767 
6 35,717 
6 56,183 
6 73,780 
6 93,884 
6 49,941 


$98,250 

167,938 

141,912 

180,061 

c 151,000 

c 23^,000 

c 312,000 

c 400,000 


1,531 
4,945 
5,811 
6,031 
3,140 
8,912 
33,611 


$17,174 


1907 


182,265 


1908 


330,903 


1909 


106,484 


1910 


39,681 


1911 


125,322 


1912 






462,230 


1913 








1914 














1915 










6 31,949 
6 49,176 








1916 

































a Includes small quantity of grahamite (manjak) produced in Barbados. 

6 Exports. c Estimated. d Exports for six months. 

e Only about 7 per cent of the quantity given represents asphalt, the remainder being bituminous 
sandstone and limestone. 

/ Figures for 1911 do not include 7,165 tons of bituminous rock for which no value was reported. 
Figures for 1913 do not include 5,112 tons of bituminous rock, valued at 85,833. 

g Includes pure soft native asphalts. 

h Includes ozokerite. 



64 



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ANNUAL PRODUCTION OF ASPHALTS 



65 



of residual asphalt. The corresponding quantities for 1914 were 111,058 tons of 
road oil and flux, and 202,729 tons of residual asphalt; and for 1915, 174,854 tons 
of road oils and fluxes, and 213,464 tons of residual asphalt. 

700.000 

650,000 

eoo.ooo 

550,000 
500,000 

450,000 

c 

o 400.000 

+■ 350,000 

i_ 

o 

i^ 300,000 

200,000 
150,000 
100,000 

50,000 


1860 1885 1890 1895 1900 1905 1910 1915 I9Z0 

Fig. 24. — Production of Asphalts and Asphaltites in the United States from 1880 to 1916. 















/ 












































1 
















1 
















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Manufactured Asphalt' 


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Production by States. The following table shows the production in short tons 
of native asphalts, asphaltites and asphaltic pyrobitumens in the United States 
during the years 1911 to 1916 inclusive, segregated according to the States in 
which they were produced. 







TABLE 


XX 










1911 


1912 


1913 


1914 


1915 


1916 


California . . 


36,481 

19,747 * 
30.846 


36,741 
10,145 
15,766 
32,514 


27,870 
17,465 
16,459 
30,810 


28,186 

18,935 

9,669 

23,098 


17,794 
19,311 
16,907 
21,739 


18,135 


Kentucky and Texas 

Oklahoma 


37,777 
15,431 
27,134 








87,074 


95,166 


92,604 


79,888 


75,751 


98,477 



* Includes Texas and K^itucky. 

The principal states producing native asphalts are California, Kentucky, Okla- 
homa, and Utah. 



66 



ASPHALTS AND ALLIED SUBSTANCES 



In California the native asphalts consist chiefly of bituminous sandstone from 
Santa Cruz and San Luis Obispo counties, together with a small quantity of bitu- 
minous hmestone produced in Santa Cruz county. In Kentucky the principal 
native asphalts consist of bituminous sandstone mined in Edmonson and Breckin- 
ridge counties. In Oklahoma, the principal output is composed of grahamite from 
two localities in Pushmataha county and one in Atoka county, also bituminous 
sandstones produced in Pontotoc and Murray counties. The principal products of 
Utah include gilsonite, wurtzilite and ozokerite, together with a comparatively 
small quantity of bituminous sandstone. In the year 1916 there was only one 
deposit of native asphalt operated in the State of Texas, consisting of an asphaltic 
limestone near Cline, in Uvalde County. 

A comparatively small quantity of asphalt-bearing shale was mined in the 
western part of the State of Colorado during the year 1916. This was used only 
for experimental work, and promises greater development. 

Ozokerite deposits have been exploited in Wasatch County, Utah, and the 
prospects of their further development appear to be encouraging. 

Imports. The asphalts imported for consumption in the United States during 
the years 1915 and 1916, are shown in the following table: 

TABLE XXI 



Imported from 



Europe: 

Germany 

Italy 

Switzerland 

England 

North America: 

Canada 

Mexico , 

West Indies: 

Barbados 

Trinidad and Tobago 

Other British West Indies . 

Cuba 

South America: 

Venezuela 

Oceania: 

Philippine Islands 



Equivalent in short tons . 



1915 



Quantity 
Hong tons). 



658 
492 
200 
774 

35 

56 

64 
92,107 



391 
28,659 



123,436 
138,252 



Value. 



$4,854 
3,438 
1,637 
9,801 

708 
755 

6,426 
498,900 



9,243 
144,595 



$680,357 



1916 



Quantity 
(long tons), 



295 

794 

124 

22 

123 

92,858 
520 
524 

36.626 



131,887 
147,713 



Value. 



$1,795 
8,599 

1,642 
381 

6,279 

494,740 

23,470 

12,701 

185,095 

10 



$734,712 



Exports. The following statistics show the asphalts exported from the United 
States during the years 1912 and 1916 segregated according to the unmanufactured 
and manufactured varieties. 



ANNUAL PRODUCTION OF ASPHALTS 



67 



TABLE XXII 





Unmanufactured. 


Manufac- 
tures of 
(value). 


Total 
value. 


Year. 


Quantity 
(Iou'j: tons). 


Value. 


1912 

1913 

1914 


39,915 
58,550 
37,24G 
38,203 
36,443 


$886,678 

1,267,625 

845,838 

735,952 

759,769 


$467,959 
411,786 
401,182 
438,685 
494,895 


$1,354,637 
1,679,411 
1,247,020 


1915 


1,174,637 


1916 


1,254,664 



Consumption of Asphalt in the United States. From the foregoing figures, it is 
possible to approximate the quantity of asphalts consumed in the United States, 
by deducting the quantity exported from the sum of the quantity marketed from 
domestic sources and the quantity imported. On this basis, the consumption of 
asphaltic materials both in the native and manufactured states in 1916 amounted 
to 1,456,634 short tons, as compared with 851,699 short tons in 1914, and 1,224,037 
in 1915. These figures should merely be regarded as a rough approximation. Un- 
fortunately, corresponding statistics pertaining to other countries are not available. 



PART II 

SEMI-SOLID AND SOLID NATIVE BITUMINOUS 

SUBSTANCES 



CHAPTER VI 
METHODS OF REFINING 

Dehydration. Most native asphalts contain more or less moisture, 
which may be. present either accidentally as hydroscopic moisture, or 
in the form of an emulsion. Trinidad asphalt is an example of the latter, 
in which about 29 per cent of water is emulsified with the asphalt and 
clay. 

Before the asphalt can be used commercially, this water or moisture 
must be removed. The process by which this is accomplished is known 
as " dehydration." The expulsion of water is brought about by heating 
the asphalt in a suitable open container constructed of iron or steel, 
which is built in two types; viz.: 

(1) Semi-cylindrical. 

(2) Rectangular. 

In either case the top is left open so that the water may be expelled 
readily. In modern plants, the heating tanks are built to contain between 
10 and 30 tons of the crude asphalt. 

The heating is effected by one of two means: 

(1) By direct fire heat, in the form of a combustion chamber underneath the 
tank, enclosed in fire bricks. Three kinds of fuel are used for this purpose, de- 
pending upon which is most readily obtained in the locality where the asphalt 
is to be refined; namely, coal, oil, or gas. Coal is burnt on a grate; oil is usually 
sprayed into the combustion chamber by compressed air or steam; and natural 
or producer gas is introduced through a suitable type of burner. 

In any case, the best practice consists in protecting the bottom of the melting- 
tank by a fire-brick arch work, so that the hot gases are compelled to circulate 
back and forth. This subjects the bottom of the tank to a more uniform tem- 
perature, and tends to prolong its life. At the same time, it economizes fuel by 

68 



METHODS OF REFINING 



69 



more thoroughly extracting the heat from the hot gases, due to the increased area 
of contact with the bottom of the tank. In some installations, the products of 
combustion are caused to zigzag back and forth under the melting-tank several 
times, to accomplish this more effectively. Some recommend the use of a perforated 
brick arch to distribute the hot gases uniformly and prevent the bottom of the 
tank from being overheated locally. 

Fire melting-tanks are usually semi-cylindrical in form, although sometimes 
they may be rectangular at the top, with a semi-cylindrical bottom (Fig. 25). 



19'- 



^ 



■>\I2^- 



Open Top 



J T-lron 



e>"x5k"x% Angle ^ Rod Fcrstened to ~7~ 
_ Iron > a Plug at bottom ~^^ 



~T 



I 



-± 



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W I 



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Fig. 25.— Steel Melting Tank. 

(2) By means of steam. In this case the heating is effected by coils of steam 
pipes contained in the tank. One and one-quarter to 1^-in. pipes are generally 
used for this purpose. According to the best practice, these are bent in coils 
composed of a continuous length of pipe without unions or joints. Another method 
consists in using cast-iron headers with straight lengths of \\ or 1^-in. pipes 
fastened in between. 

Steam is used at pressures between 125 and 150 lb. This will raise the tem- 
perature of the asphalt to 300 or 400° F. Steam has the advantage over fire 
heat in not coking the asphalt, which would tend to insulate the bottom, induce 
local overheating, and burn out the tank in a comparatively short time. 

The time of heating can be reduced materially by agitating the asphalt mechan- 
ically, since the transfer of heat through a mass of asphalt is very slow. The 
agitation may be accomplished: 

(1) By jets of dry steam which should be introduced after the temperature of 
the asphalt becomes sufficiently high to prevent condensation, and thus avoid 
excessive foaming. ^ 

(2) By jets of air. 

(3) By mechanical agitators. 

lU. S. Pat. 512,494 of Jan. 9, 1894, to R. D. Upham. 



70 ASPHALTS AND ALLIED SUBSTANCES 

During the process of dehydration, the mass is apt to froth when the temper- 
ature is raised beyond the boihng-point of water. For this reason, it is well to 
build the tanks large enough to accommodate the foam without danger of over- 
flowing. Shallow tanks are preferable to deep tanks. 

Certain types of asphalt are most difficult to dehydrate, as they foam very 
badly. Numerous devices have been used to keep down the foam, the simplest 
and most successful consisting in directing a current of hot air against the surface 
of the asphalt while it is being melted. 

The use of steam accelerates the evaporation of the more volatile constituents 
in the asphalt, and is therefore apt to cause a greater shrinkage during the dehy- 
dration than when air or mechanical mixing is used. On the other hand, air is 
apt to "oxidize" the asphalt and increase its fusing point, especially if its use is 
continued for long periods of time (see p. 350). 

Any impurities such as vegetable matter, chips of wood, etc., which rise to 
the surface when the asphalt is melted should be skimmed off. When the asphalt 
is thoroughly melted and the foaming ceases, the dehydration is complete. It is 
usually unnecessary to raise the temperature of the asphalt higher than 350° F. 
The dehydrated asphalt may be discharged: 

(1) By a valve at the bottom of the tank, permitting the asphalt to flow out 
by gravity. 

(2) By a rotary pump which may either be steam-jacketed or surrounded by 
a steam coil in close contact with the pump, the entire installation being well 
insulated. The rotary pump is usually installed above the level of the asphalt, 
and the intake pipe extended almost to the bottom of the heating-tank. 

■ (3) By means of a pneumatic lift installed below the bottom of the tank. 
The asphalt is allowed to flow by gravity into the pneumatic lift, which, by a 
suitable mechanism, automatically shuts off the flow when it is filled, and then 
admits compressed air, forcing the asphalt upward through the discharge pipe. 
The pneumatic lift may either be steam jacketed or heated with a steam coil as 
described. 

Asphalt may be pumped through pipe lines for distances of 500 feet or more. 
To effect this it must be maintained in a melted state. This is accomplished by run- 
ning a steam pipe of small diameter inside the pipe carrying the asphalt. The outer 
pipe should be well insulated. 

Sedimentation. This process is used to separate the water where it 
is present in substantial quantities, as well as any coarse particles or lumps 
of mineral matter. It can only be used successfully with asphalts or 
other forms of bitumen melting below the boiling-point of water (212° F.), 
and not carrying the water in an emulsified state. The asphalt is main- 
tained at a temperature not exceeding 200° F. by any of the devices 
described under " Dehydration," and allowed to undergo a process of 
'' Sedimentation," whereby the entrained water and coarse mineral matter 
settle to the bottom, leaving the purified asphalt on top. The latter is 
then carefully drawn off.^ Steam heating is most satisfactory for this 
purpose. 

> U. S. Pat. 580,592 of Apr. 13, 1897, to A. F. L. Bell. 



METHODS OF REFINING 71 

In some cases only a portion of the water separates by sedimentation, where- 
upon the process is supplemented by one of dehydration. The sedimentation will 
remove most of the water and has the advantage of materially shortening the 
dehydration process. A combination of the two processes will thus prove more 
effective than the use of either one alone. 

Since water usually has a higher specific gravity than melted asphalt, it tends 
to settle to the bottom of the vessel containing it. This invariably proves to be 
the case with the softer forms of native asphalt. 

Extraction. Two media have been used for this purpose, namely 
water and volatile solvents. As the methods are entirely different, they 
will be considered separately. 

Extraction by Means of Water. This method has been used with 
more or less success for extracting asphalt from asphaltic sands, sand- 
stone and limestone. It is based on the principle that water has a higher 
specific gravity than the melted asphalt, and a lower gravity than the 
accompanying mineral matter, so that when boiled together, the melted 
asphalt will rise to the surface and the mineral constituents settle to the 
bottom.^ 

To yield successfully to this msthod, the rock asphalt must possess the fol- 
lowing characteristics: 

(1) The asphalt present in the rock should have a fusing-point of not exceeding 
90° F. (K. & S. method. Test 15a.) 

(2) The particles of mineral matter should be unconsoUdated. 

(3) The grains of mineral matter should be fairly coarse to enable them to 
settle rapidly. 

Experience has shown that when the fusing-point of the asphalt contained in 
the rock is higher than 90° F., boiling water will not effect a thorough separation. 

A specimen of asphaltic sand obtained near Woodford, Okla., carrying approx- 
imately 12 per cent of asphalt and 88 per cent of sand in the form of loose, 
rounded grains between 40- and 80-mesh, separated fairly completely on boiling 
with water. The pure asphalt showed a fusing-point between 65 and 70° F. 
(See p. 99.) 

Another asphaltic sand obtained near Fort McMurray, in northern Alberta, 
carrying approximately 15 per cent of asphalt and 85 per cent of non-dompact 
sand, between 40- and 100-mesh, likewise largely separated on boiling with 
water. The fusing-point of the pure asphalt was 50° F. (See p. 106.) 

The same was true with an asphaltic sand carrying 17 per cent of asphalt 
obtained from a deposit 46 miles northwest of Edmonton, and 12 miles north of 
Onoway. In this case the pure asphalt fused at 62° F. 

A Mexican asphaltic sand carrying 16 per cent of asphalt also separated com- 
pletely on boiling with water, the fusing-point of the pure asphalt being 78° F. 

On the other hand, certain asphaltic sands obtained from various localities 
of Oklahoma, carrying between 10 and 15 per cent of asphalt refused to separate 

^ Mines and Minerals, Mar., 1903, "Refining Methods used by Tar Springs Asphalt Co., Tar 
Springs, Okla."; EriQ. d- Min. J., Dec. 17, 1903, "Asphalt Mining and Refining in Oklahoma," 
by W. R. Crane. 



72 



ASPHALTS AND ALLIED SUBSTANCES 



on boiling with water. The fusing-points of the pure asphalts were found to 
be 113° F., 118° F., and 127° F., respectively. The particles of the sand were 
substantially similar to the preceding, ranging between 40- and 100-mesh. 

Plants for the water-extraction of asphalt from rock asphalt have been in opera- 
tion in Oklahoma (sand asphalt); Texas (asphaltic limestone); Alberta, Canada 
(sand asphalt); Pechelbronn, Alsace-Lorraine (asphaltic limestone); Seyssel and 
Bastennes, France (asphaltic limestone); San Valentino, Italy (asphaltic limestone); 
and Tataros, Austria (asphaltic limestone). 

According to S. C. Ells:^ 

"The results when hot water and steam have been used have been most encouraging. 
A fairly rapid and comparatively inexpensive separation has been possible, but in actual 
commercial practice the extraction has not been sufficiently complete. Summarizing 
all evidence available to the writer, it appears that as at present understood, the use 




Voli/es to c/roiv off^ 
Mineral Matrer 1 



Fig. 26. — Apparatus for Separating Soft Asphalt from Sand by Means of Water. 

of hot water or steam, or a combination of the two, will not give a commercial extraction 
of more than 60 per cent of the bitumen contained in average bituminous sand rock. 
In attempting to secure a higher percentage extraction, a disproportionate increase in 
cost will probably result." 

The machinery for extracting asphalts with water forms the subject matter of 
various United States Letters Patent. ^ 

A cross-sectional diagram of an apparatus v>^hich gives fairly successful results is 
shown in Fig. 26. A view into the top of this extractor is shown in Fig. 27. The 
separated asphalt must be treated in accordance with the methods described under the 
heading "Dehydration," to separate the water which is mechanically carried along 
with it. If the process has been performed properly, the purified asphalt will not con- 
tain more than 5 to 7 per cent of mineral matter. The water-extraction process 
also is used for purifying ozokerite (see p. 75). 

1 " Preliminary Report on the Bituminous Sands of Northern Alberta." Dept. of Mines, 
Ottawa, Canada. 1914. 

2 655,416, Aug. 7, 1900, to Jacob Philippi; 722,500, Mar. 10, 1903, to J. S. Downard and 
B. A. Roloson; 918,628, Apr. 20, 1909, to George M. Willis; 1,190,633, July 11, 1916, to C. 
L. Cook and J. R. Price. 



METHODS OF REFINING 



73 



Extraction with Solvents. Carbon disulphide, petroleum distillates 
and benzol have been used for this purpose. This method has not proven 
successful commercially, on account of its expense. Several plants have 
been constructed in the United States for extracting asphalts from asphal- 
tic sands and sandstone. The Alcatraz Asphalt Co. of Alcatraz, CaL, 
erected an elaborate plant for treating rock carrying 10 to 16 per cent of 
asphalt. The venture, however, proved a failure through losses in solvent 
(a light distillate of petroleum), which made the cost of treatment pro- 
hibitive. The loss was due in part to unavoidable evaporation during 




Fig. 27. — Looking into the Top of the Extracting Apparatus. 



the extraction process, also to the impossibility of fully recovering the 
solvent from the extracted asphalt. 

A number of patents have been taken out covering the use of solvents:^ 

The solvent extraction process has been used successfully for recovering montan 
wax from lignite at Thuringia, Saxony; also from the mineral pyropissite, which 
is found associated with lignite at Weissenfels, near Halle, Germany. Benzol is 
generally used for this purpose, although in certain cases petroleum distillates 
have given good results. ^ 

1452,764 of May 19, 1891, to Fred Salath6: 581,546, of Apr. 27, 1897, to H. A. Frasch; 
617,226 of Jan. 3, 1899. to A. S. Cooper; 617,712 of Jan. 17, 1899, to A. F. L. Bell; 655,430 of 
Aug. 7, 1900, to A. F. L. Bell; 1,060,010 of Apr. 29, 1913, to S. R. Murray and G. E. McDermand. 

2Ger. Pats. 99,566, 101,373, 116,453, and 204,256. 



CHAPTER VII 
MINERAL WAXES 

OZOKERITE 

OzoKEKiTE is a native mineral wax, composed of the higher mem- 
bers of the CnH2n+2, and CnH2n series of hydrocarbons. It occurs 
in deposits usually associated with petroleum. Certain varieties carry 
a proportion of petroleum in solution with the wax, and the more 
petroleum present, the softer the consistency and lower the fusing-point. 
Ozokerite as ordinarily found is fairly hard, and has a comparatively 
high fusing-point, ranging from 150 to 180° F. The fusing-point has been 
recorded as high as 200° F. (K. & S. method). Ozokerite containing 
between 10 and 15 per cent of petroleum in solution, shows a fusing-point 
between 140 and 150° F. The petroleum can readily be evaporated by 
applying a moderate degree of heat, and is expelled during the refining 
process. 

The color of ozokerite depends upon the nature and extent of the 
impurities present, and ranges from a transparent yellow to a dark brown. 
In rare instances, ozokerite occurs in a dichroic variety, showing a dark 
green color by reflected light, and a pure yellow by transmitted light. 
It breaks with a conchoidal fracture, and has a characteristic waxy lustre. 
Its streak on porcelain varies from a transparent white to a pale brown. 

Ozokerite is usually found filHng veins or fissures, which are very 
irregular in structure, varying from a fraction of an inch to about two 
feet in thickness. Some extend for comparatively long distances, whereas 
others pinch out very suddenly. The veins are usually caused by faulting, 
which accounts for their irregularity and gives the vein the appearance 
of a series of pockets. (See Fig. 21.) The indications are that the 
ozokerite enters the faults or veins from below, which is borne out by 
the fact that the material mined at a depth is materially softer and 
has a lower fusing-point than that obtained near the surface. 

Ozokerite may occur in a pure state (comparatively free from mineral 
matter), which proves to be the case when it is found in vein form, or it 
may be associated with sandstone or shale. In fact, it is quite common 
for the entire region surrounding the vein to be saturated with ozokerite. 

74 



: MINERAL WAXES 75 

A paraffinaceous petroleum almost invariably occurs in the strata 
underlying the ozokerite, which would seem to indicate that the latter 
must have been produced by the slow hardening and probably also the 
oxidation of petroleum throughout centuries of time. Ozokerite, itself, 
however, is practically free from oxygen. In this particular case, there- 
fore, the effect of oxidation is to eliminate hydrogen, and form hydro- 
carbons of higher molecular weight (see p. 575) . 

The petroleum underlying the ozokerite usually contains from 8 to 
12 per cent of paraffine, which, however, is entirely different in its char- 
acter from the hydrocarbons contained in the ozokerite. This proves 
conclusively that ozokerite is not formed merely by the evaporation of 
petroleum, but must have been produced by a process of metamorphosis 
or polymerization. 

On distilling at atmospheric pressure, ozokerite decomposes, whereas when it is 
distilled under reduced pressure, its composition changes but little. 

Ozokerite as it is mined is assorted by hand picking to separate the pure 
material from that associated with earthy matter. The latter, which is known as 
"wax-stone," is broken up tor emove any lumps of rock and purified by extrac- 
tion with water, (see p. 72). The method used for this purpose is very crude, 
and consists merely in boiling the wax-stone with water in large open kettles. 
The sandstone or shale separates to the bottom and the melted ozokerite floats 
in a layer on the surface, whereupon it is skimmed off, boiled to evaporate the 
water and cast into blocks. The commercial material is comparatively free from 
mineral matter, rarely containing over 2 per cent. 

Ozokerite may be refined still further by heating to 120-200° C, with 20 per 
cent by weight of concentrated sulphuric acid. This bleaches the ozokerite, forming 
a product almost white in color, known as "ceresine." From 10 to 15 per cent 
of the ozokeiite is lost during the treatment, but the fusing-point of the product 
is increased. The final traces of acid are removed and the bleaching process com- 
pleted by adding from 5 to 12 per cent of dry residue obtained from the manu- 
facture of ''ferrocyanides." The main differences between ozokerite and ceresine 
are in the color and fusing-point. 

Ozokerite and ceresine are used in the manufacture of high-grade candles, 
colored lead pencils, for finishing off the heels and soles of shoes, manufacturing 
shoe polishes, electrical insulating purposes, and waxing floors. They are readily 
soluble in turpentine, petroleum distillates, carbon disulphide, and benzol, but 
scarcely soluble in alcohol. 

Purified ozokerite and ceresine comply with the following characteristics: 

(Test 1)* Color in mass White to yellow to brown 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Dull to "waxy" 

(Test 6) Streak Transpaient white to yellow 

(Test 7) Specific gravity at 77° F 0.85-1.00 

(Test 9a) Hardness, Moh's scale Less than 1 

(Test 96) Penetration at 32° F ^ 

Penetration at 77° F 20-30 

Penetration at 115° F 150-250 

* The numbers refer to tests, which are described in detail in Chapters XXVIII to XXXI. 



76 ASPHALTS AND ALLIED SUBSTANCES 

(Test 9c) Consistometer hardness at 32° F Above 100 

Consistometer hardness at 77° F 20-40 

Consistometer hardness at 115° F 5-15 

(Test 9d) Susceptibility factor Greater than 80 

(Test 14a) Behavior on melting Passes rapidly from a solid to a 

liquid state, melting to a very 
thin liquid of comparatively 
little viscosity 

(Test 15o) Fusing point (K. & S. method) 140-200° F. 

(Test 19) Fixed carbon |- 10% 

(Test 21a) Soluble in carbon disulphide 95-100% 

(Test 216) Non- mineral matter insoluble 0-1% 

(Test 21c) Mineral matter 0-5% 

(Test 22) Carbenes 0-3% 

(Test 23) Non-mineral matter soluble in 88° petroleum 

naphtha 75-95% 

(Test 26) Carbon 84-86% 

(Test 27) Hydrogen 16-14% 

(Test 28) Sulphur 0-1.5% 

(Test 29) Nitrogen 0-0.5% 

(Test 30) Oxygen 0-2% 

(Test 33) Solid paraffine wax 50-90% 

(Test 35) Sulphonation residue, 300-350° C.distillate. . 90-100% 
(Test 37) Saponifiable constituents 0-2% 

Very often these products are adulterated with paraffine wax, rosin, tallow, 
stearic acid or mineral fillers (such as talc, kaolin, gypsum, etc.). These may be 
detected as described on page 544. 

Ozokerite occurs in the following locafities: * 

Galicia. The most important ozokerite deposits are found in the 
Carpathian Mountains in the districts of Drohobycz (comprising Bory- 
slaw, Wolanka and Truskawiec) and Stanislau (comprising Dwiniacz, 
Straunia, Wolotkow and Niebylow). The largest deposit is located at 
Boryslaw, a small town in Galicia, and has been exploited since about 
1859. It is found at some depths below the surface, associated with 
schist and sandstone, and it is mined by means of shafts and galleries. 
About 1500 shafts have been sunk in the district. 

The following varieties of ozokerite are recognized in the Boryslaw district: 

(1) Marble Wax is very hard, of a pale yellow color, with greenish, brownish 
and black markings, giving it the appearance of marble; 

(2) Hard Wax is darker in color than Marble Wax and shows a granular 
fracture; 

(3) Fibrous Wax is characterized by its fibrous structure; 

(4) Bagga is very dark in color, and has a comparatively low fusing-point; 

(5) Kindebal is characterized by being soft, of low fusing-point and a black 
color. It contains petroleum and mineral matter. 

i"A Treatise on Ozokerite," by E. B. Gosling, School of Mines Quarterly, 16, 41, 1894; "Das 
Erdwachs, Ozokeri'te und Cerasin," by Berlinerblau, 1897; "Der Erdwachsbergbau in Boryslaw," 
J. Muck, 1903; "Mineral Waxes," by Rudolf Gregorius, 1905; "Das Wachs und seine technische 
Verwendung," Ludwig Sedna. 



MINERAL WAXES 77 

(6) Blower Wax (Matka) is a pale yellow variety of ozokerite which is squeezed 
out of the veins due to pressure of the surrounding rocks; 

(7) Lep is a variety of ozokerite associated with a substantial proportion of mineral 
matter. 

The deposit at Wolanka is smaller than that at Boryslaw. The occurrence at 
Truskawiec differs from the others by the presence of a comparatively large per- 
centage of sulphur. The ozokerite in this locality is associated with native sul- 
phur, lead sulphide, gypsum, and petroleum. 

At Dwiniacz, Straunia and Wolotkow, about 70 miles south of Boryslaw, the 
ozokerite veins are located some distance below the surface, in beds of clay between 
layers of shale. Considerable ozokerite has been mined in this district, and par- 
ticularly at Dwiniacz. The veins vary in size from I in. to about 1 ft. The rock 
in the vicinity of the veins is impregnated with wax containing an average of 
2 per cent. 

Rumania. Deposits of ozokerite are also found in a spur of the Car- 
pathian Mountains in the province of Moldavia in Rumania. It has 
been mined in several localities, the largest vein occurring in the City of 
Slanik, beneath a bed of bituminous shale, associated with a vein of 
cannel coal. This deposit is characterized by its high fusing-point, 
in the neighborhood of 200° F. (K. & S. method). 

Russia. Small deposits occur in Transcaspian Province on the north 
slope of the Caucasian Mountains at Kouban, also on the Islands of 
Swajtoi and Cheleken in the Caspian Sea. The largest deposit in Russia 
occurs at the last named place accompanied by petroleum in strata of 
clay and chalk. ^ Minor deposits are also said to occur at Baku. 

United States. The most important deposit occurs in Wasatch 
County, Utah, near Colton in Utah County,^ in a bed of oil shale. The 
veins extend from about two miles west of Colton to within a few hundred 
yards west of the railroad station of Soldier Summit, or a total distance 
of twelve miles. These oil shales overlie a bed of clay in which the ozo- 
kerite occurs. A peculiar feature of this deposit is the occurrence of fossil 
shells together with other animal remains. The veins have been worked 
during 1916, about 4 tons having been mined, and part of the output re- 
fined and marketed in the form of ceresine. The following analytical 
results have been reported : ^ 

(Test 1) Color in mass Yellowish brown 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Dull 

(Test 6) Streak Pale yellow 

(Test 7) Specific gravity at 77° F 0.891 

» " The Ozokerite Industry on the Island of Cheleken," Petroleum World, 14, 136, 1917. 

2 "The Ozokerite Deposits of Soldier Summit, Utah," by W. C. Higgins, Salt Lake Min. Rev., 
18, 17, 1916; "Ozokerite in Utah," L. O. Howard, Mining Sci. Press, 112, 909, 1916. 

3 J. Ind. Eng. Chem., 5, 973, 1913. 



78 ASPHALTS AND ALLIED SUBSTANCES 

(Test 9a) Hardness, Moh's scale ...,..; Less than 1 

(Test 96) Penetration at 77° F 30 

(Test 16) Volatile, 212° F., 1 hr 0.0% 

Volatile, 325° F., 7 hrs 45.41% 

Volatile, 400° F., 7 hrs 65.2% 

(Test 19) Fixed carbon 9.6% 

(Test 20) Distillation test: 

0-150° C 0.21% 

150-200° C 8.91 

200-250° C 8.38 

250-300° C 17.69 

300-350° C 25.89 

350-400° C 26.85 

Total volatile 78 . 93% 

Non-v^olatile (fixed carbon and ash) 10.07 

Total 100.00% 

(Test 21a) Solubility in carbon disulphide 99 . 46% 

(Test 216) Non-mineral matter insoluble . 50% 

(Test 21c) Free mineral matter 0.046% 

(Test 22) Insoluble carbon tetrachloride 2.51% 

(Test 23) Soluble in 62° naphtha 81.71% 

(Test 24) Grams soluble in 100 grams of the following solvents 
(cold): 

Amyl acetate 1 

Amyl alcohol Insoluble 

Amyl nitrate 7 

Aniline Insoluble 

Benzol . .18 

Carbon disulphide Soluble in all proportions 

Carbon tetrachloride Soluble in all proportions 

Chloroform Soluble in all proportions 

Ethyl acetate 1 

Ethyl alcohol Insoluble 

Ethyl ether 13 

Naphtha, 62° 7 

Nitrobenzene Insoluble 

Propyl alcohol Insoluble 

Toluol Very soluble 

Tvirpentine Very soluble 

(Test 26) Carbon 85 . 35% 

(Test 27) Hydrogen 13.86% 

(Test 28) Sulphur 0.29% 

(Test 29) Nitrogen . 36% 

At Thrall, Texas, in the so-called Thrall Oil Field, another deposit has been 
reported. The crude material is soft, due to the petroleum associated with it, 
and of a dark brown color. It has a strong odor of petroleum, and a specific 
gravity at 77° F. of 0.875. On being heated to 100° C, it loses 14.72 per cent 
in weight, and at 180° C. a total of 23.14 per cent. On being freed from petro- 
leum, it shows a fusing-point of 175° F. 

HATCHETTITE OR HATCHETTINE 

The above names are assigned to a soft variety of ozokerite fusing in the 
neighborhood of 120° F. (K. and S. method). It varies in specific gravity from 

1 J. Ind. Eng. Chem., 8, 1095, 1916. 



MINERAL WAXES 79 

0.90 to 0.98 at 77° F., and has a yellowish-white, yellow or greenish-yellow color. 
It was named after C. Hatchett, an Enghsh chemist (1765-1847). It is found 
near Merthyr-Tydvil in Glamorganshire, England, also at Loch Fyne in Argyl- 
shire, Scotland. 

SCHEERERITE 

A native wax found in a bed of hgnite near St. Gallen, Switzerland. It 
occurs in the form of crystals (monoclinic) and of a white, gray, yellow, green or 
pale reddish color. It is more or less translucent to transparent, and has a waxy 
feel. It is composed chiefly of the members of the paraffine series, and fuses at a 
temperature of 110-115° F. 

KARAITE 

This is a waxy hydrocarbon similar to ozokerite or scheererite, which has 
been found in meteorites. It is only of scientific interest and has no commercial 
importance. 

MONTAN WAX 

As stated previously, montan wax is dissolved from certain non- 
asphaltic pyrobitumens by means of volatile solvents. The lignite or 
pyropissite is first dried, then granulated, and finally extracted. The 
extract is evaporated to recover most of the solvent. The last traces 
of solvent are expelled from the montan wax by distillation with steam, and 
recondensed. The crude wax differs widely according to the source, 
Thuringian lignites yielding a hard and brittle wax, whereas Bohemian 
lignites yield a softer product. 

Ninety per cent of the montan wax present in the lignite is removed 
in this manner. About 10 to 15 per cent of the solvent is lost, but the 
high price obtainable for montan wax renders this permissible. Usually 
8 to 10 per cent of montan wax is extracted from Thuringian lignite 
based on the dry weight of the latter. In exceptional cases, as high 
as 20 per cent has been obtained. Pyropissite yields between 50 and 70 
per cent of montan wax based on its dry weight. Unfortunately, the 
supply of pyropissite is largely exhausted. 

According to Graefe/ the following percentages of montan wax are 
extracted by benzol from the dried minerals: 

Bohemian Lignite 1 . 29% 

Texas Lignite 2.07% 

Lignite from the region of the Rhine ; 4 . 70% 

Lignite from Vladivostok 5 . 38% 

Lignite from Thuringia, Saxony 9 . 03% 

Pyropissite 69.50% 

» "Braunkohlenteer-Industrie," Halle. 1908. 



80 ASPHALTS AND ALLIED SUBSTANCES 

The montan wax industry is not practised in the United States, but 
is locaHzed in Saxony.^ 

Montan wax contains esters of acids possessing high molecular weight, free acids 
and a small quantity of substances containing sulphur. Various formulae have been 
assigned to it, including CieHsaO, C29H68O2, C29H68O2, and C42H86O. 

At ordinary temperatures it decomposes when distilled. It may, however, be 
purified by distilling with superheated steam in vacuo. In this manner the fol- 
lowing products are obtained: 

(1) Pure odorless montan acid; 

(2) Refined montan wax; 

(3) A bright yellow wax containing parafSne; 

(4) A residue containing paraffine; 

(5) An acid-free cable pitch. 2 

On heating with glycerine, an ester is obtained which has a much higher fusing- 
point (in the neighborhood of 200° F.). 

Commercial montan wax complies with the following characteristics: 

(Test 1) Color in mass: 

Crude montan wax Dark brown 

Product obtained by distillation in vacuo Almost white 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Waxy 

(Test 6) Streak on porcelain Yellowish brown to white 

(Test 7) Specific gravity at 77° F . 90-1 . 00 

(Test 9c) Hardness at 77° F. (consistometer). Above 100 

(Test 9d) Susceptibility factor > 100 

(Test 10) Ductility at 77° F 0.0 

(Test 13) Odor on heating Pleasantly aromatic 

(Test 14o) Behavior on melting Passes rapidly from i,he 

solid to liquid state 

(Test I60) Fusing-point (K. and S. method) 170-200° F. 

N.B. — Montan wax obtained from pyropissite has a higher fusing-point 

than that obtained from lignite; namely, between 190 and 200° F. 

(Test 17) Flash point 550 to 575° F. 

(Test 19) Fixed carbon 2-10% 

(Test 2I0) Solubility in carbon disulphide Greater than 98% 

1" Montan Wax, and Its Behavior on Distillation," J. Marcusson and H. Smelkus {Chem. Zeit. 
41, 129 and 150, 1917). According to Eisenreich montan wax shows the following figures, when tested 
in accordance with special methods devised by him: {Chem. Rev. Fett-Harz-Ind., 16, 211, 1909). 

Saponification value 95 

Acid value 93 

Ester value 1.5 

Acetyl acid value 93 

Acetyl value 11 

Unsaponifiable 29% (M.-pt. = 146° F.) 

Iodine value 12 

According to Marcusson {Chem. Rev. Fett-Harz-Ind., 15, 193, 1908) montan wax tests as follows, 
when examined by the usual methods applicable to fats and oils: 

(Test 37a) Acid value 29-33 

(Test 37c) Ester value 28-73 

(Test 37d) Saponification value 50-85 

2 Ger. Pat; 260,697 of Mar. 29, 1911. 



MINERAL WAXES 81 

(Teat 216) Non-mineral matter insoluble 0-2% 

(Test 21c) Mineral matter Less than 2% 

(Test 23) Soluble in 88° naphtha 80-100% 

(Test 24) Solubility in ether and alcohol Only partly soluble 

(Test 26) Carbon 82-83^ % 

(Test 27) Hydrogen 14-14^% 

(Test 28) Sulphur Less than 1.5% 

(Test 29) Nitrogen Trace 

(Test 30) Oxygen 3-6% 

(Test 33) Paraffine 0-10% 

(Test 35) Sulphonation residue 0-10% 

(Test 37) Saponifiable 50-80% 

(Test 41) Diazo reaction No. 

(Test 42) Anthraquione reaction No. 

Montan wax is used for manufacturing shoe polishes, phonographic records, elec- 
trical insulating materials, and the like. 



CHAPTER VIII 
NATIVE ASPHALTS OCCURRING IN A FAIRLY PURE STATE 

Undee this heading will be considered the most important asphalt 
deposits containing less than 10 per cent of mineral matter figured on the 
dry weight. These include exudations or seepages of liquid or semi- 
liquid asphalts, also surface overflows and lakes. Most of these are 
characterized by being liquid to semi-liquid at normal atmospheric tem- 
perature, and by containing a comparatively large proportion of volatile 
matter. Only a few of these deposits are of value commercially. 

The principal depo&its are as follows: 

NORTH AMERICA 

United States 
Kentucky. 

Breckenridge County. The so-called "Tar Springs" situated about 4 miles 
south of Cloverport on Tar Creek, have been known for many years. They occur 
as seepages of pure, soft asphalt at the base of an overhanging cliff of sandstone 
where it joins a stratum of limestone. The asphalt is accompanied by water 
charged with sulphur compounds, and the surrounding rocks abound in marine 
fossils. 

Grayson County. Similar seepages abound along Big Clifty Creek and its trib- 
utaries, in the vicinity of Grayson Springs station. Some exude from sandstone 
and others from clay or shale. The seepages carry between 5 and 10 per cent 
of free mineral matter, the balance consisting of a very soft, "stringy" asphalt 
containing a large proportion of volatile ingredients and yielding about 15 per 
cent of fixed carbon. 

Oklahoma. 

There are only a few minor occurrences of pure asphalt found in the form of 
seepages in Oklahoma, including the following: 

Carter County. NE i, Sec. 10, T 2 S, R 2 W; 10 miles north of Wheeler. 

Murray County. SW i, SE i. Sec. 15, T 1 S, R 3 E; 3 miles south of Sulphur. 

Neither of these has any commercial importance. 

Utah. 

Uinta County. A pure, solid asphalt is found in Tabby Canyon, a branch of 
the Duchesne River, 8 to 9 miles south and west of the town of Theodore and 

82 



NATIVE ASPHALTS OCCURRING IN A FAIRLY PURE STATE 83 

about 30 miles west of Ft. Duchesne. It has been exploited under the name 
" tabbyite"^and tests as follows: 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Bright 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1.006-1.010 

(Test 9a) Hardness, Moh's scale Less than 1 

(Test 96) Penetration at 77° F 

(Test 9c) Consistency at 77° F 80 . 

(Test 146) In flame Softens and flows 

(Test 15a) Fusing-point (K. and S. method) 178° F. 

(Test 16) Volatile matter, 325° F. in 7 hrs 2.78% 

Volatile matter, 400° F. in 7 hrs 6.40% 

(Test 19) Fixed carbon 8.08-9.2% 

(Test 21a) Soluble in carbon disulphide 94.7-92.1% 

(Test 216) Non-mineral matter insoluble 0.5- 1.1% 

(Test 21c) Free mineral matter 4.8- 6.8% 

(Test 22) Carbenes 0.0% 

(Test 23) Soluble in 88° naphtha 61% 

(Test 25) Carbon 82% 

(Test 26) Hydrogen 11% 

(Test 27) Sulphur 2% 

(Test 28) Nitrogen 3% 

Undetermined 2% 

Boxelder County. A pure viscous asphalt deposit occurs below the bed of 
Great Salt Lake, about 10 miles south of Rozel, in the Promintory Range ^ It 
is found in a series of horizontal veins 3 to 5 ft. thick interposed between beds 
of clay, continuing to a depth of at least 140 ft. It is highly probable that a 
lake of asphalt occurred at this point centuries ago, which in time became covered 
with sediments, giving rise to a series of veins. 

At the present time, masses of asphalt exude through the unconsolidated material 
at the bottom of the lake, and rise to the surface in lumps 1 to 2 ft. in diam- 
eter. This occurrence corresponds very closely with the Dead Sea deposit (see 
p. 136). On analysis, the asphalt tests as follows: 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Very bright 

(Test 6) Streak Black 

(Test 96) Penetration at 32° F. (200 g. in 60 sees.) 12 

Penetration at 77° F. (100 g. in 5 sees.) 50 

Penetration at 115° F. (.50 g. in 5 sees.) 170 

(Teat 10a) Ductility at 77° F 70 cms. 

(Test 16) Volatile at 300° F. in 24 hrs 2.33% 

(Test 21a) Soluble in carbon disulphide 95.00% 

(Test 216) Non-mineral matter insoluble 1.84% 

(Test 21c) Free mineral matter 3.16% 

California. 

Kern County. The deposits of asphalt occur in the so-called "Asphalto Region" 
in the western part of Kern County, about 50 miles west of Bakersfield, in the 
form of large springs; also as veins. The character of the deposit varies greatly, 
both in consistency and purity. The superficial overflow covers an area of 7 

J/. Ind. Eng. Chcm., 5, 973, 1913. 

«"Oil and Asphalt Prospects in Salt Lake Basin, Utah," Bull, No. 260, U. S. Geol. Survey, 
Wash., p. 473. 1905. 



84 ASPHALTS AND ALLIED SUBSTANCES 

acres in a layer 2 to 4 ft. thick overlying sand and clay. Part of it has hardened 
on account of exposure to the elements, and other portions are still soft and 
viscous. A vein of asphalt also occurs in the vicinity of the overflow, filling a 
fault, varying from 2 to 8 ft. in width, averaging about 4 ft. The nature of the 
asphalt in the vein is similar to that of the overflow. 

The asphalt carries from 3 to 30 per cent mineral matter, mostly sand and 
clay, also gas, which is evidenced by the fact that it loses between 5 and 15 per 
cent in weight on being heated to 212° F. for one hour. The run of the mine 
averages 85 per cent asphalt, 10 per cent mineral matter and 5 per cent moisture 
and gas. It is refined by heating, which drives off the water and gas and per- 
mits a certain amount of the mineral matter to settle out. According to Richard- 
son ^ the refined asphalt tests as follows: 

(Test 4) Fracture Semi-conchoidal 

(Test 5) Lustre Bright to dull 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1.06 

(Test 9b) Penetration at 77° F 0-27 

(Test 15d) Temperature at which it flows 180° F. 

(Test 16) Volatile matter, 325° F., 7 hrs 6.6% 

Volatile matter, 400° F., 7 hrs 19.9% 

(Test 19) Fixed carbon 8.0% 

(Test 21a) Soluble in carbon disulphide 89.8% 

(Test 215) Non-mineral matter insoluble 3.4% 

(Test 21c) Free mineral matter 6.8% 

Total 100.0% 

(Test 22) Carbenes 0.3% 

(Test 23) Soluble in 88° naphtha 53.4% 

(Test 34) Saturated hydrocarbons 28.6% 

The asphalt resembles gilsonite in its outward appearance, but is considerably 
softer, yielding a smaller percentage of fixed carbon. Richardson infers that the 
asphalt has been metamorphized only part way to gilsonite. 

This deposit of asphalt is not being worked at the present time, but is of 
interest from the scientific view-point. 

A sample of liquid asphalt taken from seepages in the so-called "McKittrick 
Region," in Kern County, shows specific gravity at 77° F., of 0.99, and 16 per 
cent loss on being heated to 400° F. for seven hours. In its original state it is 
very soft and sticky. 

Santa Barbara County. Veins of high-grade asphalt occur in La Graciosa hills 
about 4 to 5 miles east of the town of Graciosa in the so-called Santa Maria 
Region. These are irregular in formation, extending through shale and sandstone, 
and varying from several inches to 2 ft. in width. Associated with these veins 
are beds of impregnated asphaltic shale, extending over an area of a mile or 
two, and containing a variable percentage of asphalt. One of the striking features 
of these occurrences is the presence of marine fossils in the veins and surrounding 
shale, indicating that the asphalt is of animal origin. 

San Luis Obispo County. A large surface deposit of soft asphalt produced by 
seepage from the surrounding shale occurs at Tar Spring Creek, a tributary of 
the Arroyo Grande, 20 miles southeast of San Luis Obispo, covering an area of 
200 ft. in diameter and 3-15 ft. deep. As it exudes from the shale the asphalt 
is soft and accompanied with sulphurous water; near the edge of the deposit 
^ "Modern Asphalt Pavement," loc. cit., p. 205. 



NATIVE ASPHALTS OCCURRING IN A FAIRLY PURE STATE 85 

it appears quite hard, and at the edge it verges towards brittleness. No ana- 
lytical results are available. 

Oregon. 

Coos County. An unusual type of asphalt occurring in beds of coal has been 
reported at the Newport Mine at Libby, and Ferrey's Mine at Riverton, in the 
Coos Bay coal field. It is hard and brittle, and similar to coal in appearance. 
About one-third of the non-mineral matter is insoluble in carbon disulphide, 
yet the material fuses at a comparatively low temperature (about 300° F.), 
and has a specific gravity of less than 1.10 at 77° F. It may be regarded as a 
metamorphized asphalt or a glance pitch. It constitutes one of those sub- 
stances encountered occasionally, falling on the border line; so th"+ it becomes 
a difficult matter to arrive at its correct classification. For a long time it was 
known as a "Pitch Coal." ^ The following data would seem to indicate that it 
partakes of the properties of an asphalt rather than of a glance pitch: 

(Test 4) Fracture Hackly 

(Test 5) Lustre Fairly dull 

(Test 6) Streak Black 

(Teat 7) Specific gravity at 77° F 1.09 

(Test 9a) Hardness, Moh's Scale About 1 

(Test 9b) Penetration at 77° F 

(Test 9c) Consistency at 77° F Above 100 

(Test 146) In flame Softens and flows 

(Test 15a) Fusing-point (K. and S. method) 302° F. 

(Test 19) Fixed carbon 10-13% 

(Test 21a) Soluble in carbon disulphide 60.3-63.5% 

(Test 216) Non-mineral matter insoluble 31.5-36.5% 

(Test 21c) Free mineral matter 2 - 8 % 

(Test 23) Soluble in 88° naphtha About 10% 

(Test 27) Sulphur 0.5- 1.0% 

Mexico 
State of Tamaulipas. 

Asphalt springs occur at numerous points along the Tamesi River, which, 
according to Richardson, ^ show the following characteristics: 

(Test 7) Specific gravity at 77° F 1 . 04- 1.12 

(Test 96) Penetration at 77° F 40 -16 

(Test 16) Loss at 212° F. until dry 10 -20% 

Loss at 325° F. for 7 hrs. (refined material) 1.5-4.8% 

Loss at 400° F. for 7 hrs 4.3- 8.9% 

(Te.st 17) Flash-point 308° F. 

(Test 19) Fixed carbon 12.6-16.1% 

(Test 21o) Solubility in carbon disulphide ^refined material) 89.1-99.0% 

(.Test 216) Non-mineral matter insoluble 0.5-1.8% 

(Test 21c) Free mineral matter 0.5- 9.1% 

Other deposits in the neighborhood show a larger proportion of mineral matter, 
often running as high as 33 per cent. 

Chijol. Asphalt springs occur also near Chijol, 25 miles west of Tampico. 
They are comparatively soft in consistency, testing over 90 per cent soluble in 
carbon disulphide, with less than 10 per cent mineral matter. 

1 "Nineteenth Annual Report," U. S. Geol. Survey, Wash., D. C, Part III, 368, 1899. 

2 "Modern Asphalt Pavement," loc. cit., p. 197. 



86 ASPHALTS AND ALLIED SUBSTANCES 

State of Vera Cruz. 

Tuxpan. Similar deposits are found in the neighborhood of Tuxpan, some 
distance from the Tuxpan River, having the same general characteristics as the 
preceding. Analyses show that 90 per cent is soluble in carbon disulphide, with 
less than 10 per cent of mineral matter. 

Chapapote. Similar deposits are found 15 miles from Timberdar at the head 
of the Tuxpan River, of an exceedingly pure character, testing 99 per cent soluble 
in carbon disulphide, and less than 1 per cent mineral matter. The asphalt 
varies in consistency from a semi-liquid to a comparatively hard soUd, depending 
upon the length of time it has been exposed to the weather. 

Cuba 
Province of Matanzas. 

A pit filled with pure liquid asphalt has been reported in the neighborhood 
of Santa Catalina. This occurs in a bed of serpentine, and originally produced 
in the neighborhood of 20 barrels of semi-liquid asphalt a day, derived presum- 
ably from underlying petroleum-bearing strata. Other pits in the neighborhood 
similarly yield liquid asphalt 

SOUTH AMERICA 

Venezuela 
State of Bermudez 

The so-called Bermudez ''Pitch Lake" known as ''La Felicidad" occurs 
on the western side of the Gulf of Paria, opposite the Island of Trinidad. 
The asphalt " lake " extends over 900 acres in swampy land, at the mouth 
of the Guanaco River, and varies in depth from 2 to 9 ft., averaging 4 ft. 
The surface is covered with vegetation and pools of water. A typical 
view is shown in Fig. 28. The lake represents the exudation of soft 
asphalt from springs distributed at different points over its area, and 
constitutes one of the largest deposits of pure asphalt yet discovered. 

Its consistency varies in different parts of the lake. Where it exudes 
from the springs, it is quite soft, and disengages gas freely and copiously. 
The surface of the deposit slowly hardens on exposure to the weather, 
forming a crust varying from several inches to several feet in thickness, 
and sufficiently firm to support the weight of a man. The asphalt under- 
neath, however, is still soft and semi-liquid, and there are numerous 
breaks through the surface from which the soft asphalt oozes. At the 
edge of the lake the asphalt is hard and brittle, due to the evaporation 
of the volatile constituents by the heat of the sun. Certain portions 
of the lake have been converted into a cokey mass as a result of fires 
which must have swept over the lake years ago, due probably to the 
combustion of vegetation growing profusely at the edges. 



NATIVE ASPHALTS OCCURRING IN A FAniLY PURE STATE 87 . 






Courtesy of Barber Asphalt Paving Co. 
Tig. 28.— View of Bermudez Asphalt Lake. 




Courtesy of Barber Asphalt Paving Co. 

Fig. 29. — ^Transporting Bermudez Asphalt. 



88 ASPHALTS AND ALLIED SUBSTANCES 

The asphalt is gathered by hand, dumped into small cars and run to a 
wharf some miles distant where it is loaded on steamers, as is shown in 
Fig. 29. 

According to Richardson ^ the dried crude Bermudez asphalt has the 
following composition: 

(Test 1) Color in mass Black 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Bright 

(Test 7) Specific gravity at 77° F 1 . 005 - 1 . 075 

(Test 15d) Temperature at which it "flows" 135 -188° F. 

(Test 16) Volatile at 400° F. in 7 hrs. (dried material) 5.81-16.05% 

(Test 21o) Soluble in carbon disulphide 90 -98% 

(Test 216) Non-mineral matter insoluble 0.62- 6.45% 

(Test 21c Free mineral matter 0. 50- 3 . 65% 

The crude Bermudez asphalt is melted to drive off the moisture and 
gas. The water which is present is derived from the heavy rains and by 
overflows from the surrounding country. It is not emulsified with the 
asphalt as is the case with the Trinidad deposit. The percentage of 
water varies from 10 to about 40 per cent as a maximum. 

Refined Bermudez asphalt tests as follows r^ 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Very bright 

(Test 6) streak Black 

(Test 7) Specific gravity at 77° F 1 . 06-1 . 085 

(Test 9a) Hardness on Moh's scale Less than 1 

(Test 9b) Penetration at 77° F 20-30 

(Test 9c) Consistency at 115° F 7.7 

Consistency at 77° F 32 . 7 

Consistency at 32° F 93 . 8 

(Test 9d) Susceptibility factor 62 . 5 

(Test 106) Ductility at 115° F 14.5 

Ductility at 77° F 11 

Ductility at 32° F 

(Test 11) Tensile strength at 115° F 0. 60 

Tensile strength at 77° F 3 . 45 

Tensile strength at 32° F 10 . 5 

(Test 15a) Fusing-point (K. and S. method) 130 -140° F. 

(Test 15d) Temperature at which the asphalt "flows" 170 -180° F. 

(Test 16) Volatile matter, 325° F., 7 hrs 3.0- 6.0% 

Volatile matter, 400° F., 7 hrs 8.0- 10.0% 

(Test 19) Fixed carbon 12.9- 14.0% 

(Test 20) Distillation test: 

0-150° C 9.89% 

150-200° C 7.99% 

200-250° C 16 . 08% 

250-300° C 21.12% 

Above 300° C 0.0% 

Residue 44 . 92% 

1 "The Modern Asphalt Pavement," loc. cit., p. 183. 

2 Ibid., loc. cit., p. 186; Bardwell, /. Ind. Eng. Chem., 5, 973, 1913; 6, 865, 1914. 



NATIVE ASPHALTS OCCURRING IN A FAIRLY PURE STATE 89 

(Test 21a) Solubility in carbon disulphide. . '. " ' ." 92 - 97% 

(Test 216) Non-mineral matter insoluble 1.5- 4 . 0% 

(Test 21c) Free mineral matter 1.5- 6.5% 

(Test 22) Carbenes 0.0- 1.0% 

(Test 23) Solubility in 88° naphtha 60 -75% 

(Test 24) Grams soluble in 100 grams of the following solvents 
(cold): 

Amyl acetate .' 37 

Amyl alcohol Insoluble 

Amyl nitrate 39 

Aniline Insoluble 

Benzol 36 

Carbon disulphide In all proportions 

Carbon tetrachloride In all proportions 

Chloroform 23 

Ethyl acetate 24 

Ethyl alcohol Insoluble 

Ethyl ether 145 

Nitrobenzene 24 

Propyl alcohol Insoluble 

Toluol 33 

Turpentine 116 

(Test 26) Carbon 82 . 88% 

(Test 27) Hydrogen 10.79% 

(Test 28) Sulphur 5 . 87% 

(Test 29) Nitrogen . 75% 

Total 100.29% 

(Test 33) Parafline 0.0% 

(Test 34) Saturated hydrocarbons 23- 25% 

(Test 37d) Saponification value 28 . 

(Test 38a) Free asphaltous acids " 3 . 5% 

(Test 386) Asphaltous anhydrides 2.0% 

(Test 38c) Asphaltencs ; 35.3% 

(Test 38d) Asphaltic resins 14 . 4% 

(Test 38e) Oily constituents 39 . 6% 

La Brea Deposit. This also occurs as an overflow in the form of a 
lake, on the Island of Padernales in the delta of the Orinoco River, a 
comparatively short distance from the Bermudez Lake. It is about 
3,200 ft. long, and an average of 200 ft. wide. Similar deposits on a 
smaller scale are found on the neighboring islands of Paquero and Del 
Plata. 



State of Zulia 

Maracaibo Deposit. This occurs on the Limon River located south- 
west of the Gulf of Maracaibo. It is also in the form of an overflow 
exuding from a number of springs. The asphalt is gathered by means of 
picks and shovels and transported in barges down the Limon River to 
the Gulf, where it is loaded on board steamers. It melts at a higher 
temperature than the Bermudez asphalt, and possesses a very strong and 
characteristic sulphurous odor. 



90 ASPHALTS AND ALLIED SUBSTANCES 

According to Richardson ^ it tests as follows: 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Very bright 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1 . 06-1 . 08 

(Test 9a) Hardness, Moh's scale Less than 1 

(Test 96) Penetration at 77° F 20-30 

(Test 13) Odor on heating Characteristic, strongly 

sulphurous 

(Test 15d) Temperature at which it flows 200 -250° F. 

(Test 16) Volatile at 325° F., 7 hrs 1 . 5-5% 

Volatile at 400° F., 7 hrs 4.7- 6.0% 

(Test 19) Fixed carbon 15 . 0- 19 . 0% 

(Test 21a) Solubility in carbon disulphide 92 - 97% 

(Test 21b) Non-mineral matter insoluble 1.4- 5.0% 

(Te.st 21c) Free mineral matter 1.5- 6 . 0% 

(Test 22) Carbenes 1.5% 

(Test 23) Solubility in 88° naphtha 45 -55% 

(Test 34) Saturated hydrocarbons 25 -30% 

EUROPE 

France 
Department of Puy-de-D6me. 

In the vicinity of Clermont Ferrand, seepages of soft asphalt exude from 
crevices in the rock, containing 90 per cent of asphalt, 7 per. cent water, and 
3 per cent mineral substances. The exudations are comparatively small in amount, 
and the asphalt has never proved of importance commercially. 

Albania 
Selenitza. 

At the junction of the Vojutza and Sauchista Rivers, there occurs a fairly 
large deposit of moderately hard asphalt in sandstone and conglomerate, in veins 
as wide as 10 ft. Marine fossils are associated with this deposit, indicating it 
to be of animal origin. The asphalt breaks with a conchoidal fracture, showing 
a high lustre. It contains between 8 and 14 per cent of mineral matter, averaging 
about 10 per cent. Comparatively large quantities have been mined. 

Greece 
Zante. 

An extensive deposit of asphalt occurs in the southern portion of the Island of 
Zante, in the form of springs and seepages. The asphalt is very soft in consist- 
ency, having a specific gravity of 1.00 to 1.02 at 77° F., and carrying but a trace 
of mineral matter, with a fairly large proportion of water in emulsion. The 
springs occur in a region of clay and limestone, more or less saturated with petro- 
leum. These deposits have been worked for many generations. (See p. 10.) 
The asphalt is refined in a crude way by the natives who use it for calking the 
seams of ships, and as a mortar for cementing together the stones of buildings, 
following the same method as practiced centuries ago. 

i"The Modern Asphalt Pavement," loc. cit., pp. 190-191. 



NATIVE ASPHALTS OCCURRING IN A FAIRLY PURE STATE 91 

ASIA 

Syria 
Deposits have been reported at Sohmor, about 30 miles south of the City of 
Beirut, also at Latakia in North Syria. They have never been worked to any 
extent.^ 

Eastern Siberia 
Sakhalin 

Province of Nutowo. An asphalt lake occurs on the east coast of the Island of 
Sakhalin in a swampy valley, associated with a very thick variety of petroleum, 
exuding in the neighborhood. Where the asphalt emanates from the springs, it 
is very soft and sticky, but towards the edges of the lake it is hard and brittle. 
The asphalt has a rather strong odor, and contains a substantial quantity of vol- 
atile matter. After being air-dried, it carries 0.75 per cent of moisture, 0.22 per 
cent of ash, and the balance pure asphalt containing 0.80 to 0.85 per cent sulphur. 
It is estimated that at least 400,000 tons of asphalt, averaging 0.9 per cent of 
mineral matter, are present, in the lake. Up to the present, the deposit has not 
been developed commercially. ^ 

Philippine Islands 
Island of Leyte 

Several asphalt deposits have been found in this region, one near the head of 
the Butason River, about 6 miles from the Barrio of Campocpoc, on the north- 
western coast of the island, and another near the town of Villaba.^ These occur in 
limestone and sandstone, and extend over an area 12 miles long. Outcrops of 
various grades of asphalt have been reported, including the solid, viscous and 
hquid tjT)es. Both pure and rock asphalts are found, the latter carrying a variable 
proportion of sand. Two varieties of pure, hard asphalt were examined by the 
writer, one having a black color in mass, and a glossy, black, conchoidal fracture; 
another having a dark brown color in mass, with a hackly, dull fracture. They 
tested as follows: 

Black Asphalt Brown Asphalt 

(Test 4) Fracture Conchoidal Hackly 

(Test 5) Lustre Bright Dull 

(Test 6) Streak on porcelain Black Yellowish brown 

(Test 9c) Consistency at 77° F 31.7 Greater than 100 

(Test 10) Ductility at 77° F h 

(Test 15a) Fusing-point (K. and S. method) 287^° F. 138° F. 

(Test 21a) Solubility in carbon disulphide 98% 99% 

(Test 21c) Free mineral matter 2% 1% 

(Test 37) Saponifiable matter None None 

The brown variety is unique. It is somewhat similar in physical properties 
to montan wax, but it is very much more friable. When melted it turns black in 
mass, becoming lustrous (although it still shows a yellowish brown streak). The 
black asphalt is not classed as an asphaltite in view of its comparative softness 
at 77° F. These deposits have not 3^et been exploited commercially. 

1" Reports from the Consuls of the U. S., 42, 228, 1893. 
^Pet. Rev. and Min. News., 9, [237], 2.30. 

3 Commerce Report No. 170, p. 358, Wash., D. C, Jul. 22, 1915; also Philippine Journal of 
Science, lOA, p. 241, 1915. 



CHAPTER IX 
NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 

NORTH AMERICA 

United States 
Kentucky 

All the deposits in the State of Kentucky are composed of sand and sandstone, 
carrying between 4 and 12 per cent of soft asphalt filling the interstices. ^ 

Carter County. This deposit occurs one-half mile southeast of the town of Soldier, 
and consists of unconsolidated quartz grains held together by 4 to 10 per cent of 
asphalt, which is comparatively soft and contains a goodly proportion of volatile 
matter, 

Breckinridge County. This deposit is located from 2 to 4 miles south of Gar- 
field, and is composed of unconsolidated quartz grains carrying 4 to 8 per cent 
of asphalt. It forms a hillside ledge about 14 ft. thick with an overburden of 10 
to 20 ft. The deposit has not been worked to any great extent in recent years, 
although formerly it was of considerable interest in the paving industry. Other 
prospects occur in this neighborhood, but these have not been developed. 

Grayson County. Two deposits have been worked in this locality, one 3 miles 
southwest, and the other 9 miles north of Leitchfield. The former occurs in a 
stratum 5 ft. thick, impregnated with 6 per cent of asphalt, in an unconsolidated 
quartz sand. The second was formerly one of the most active mines in Kentucky, 
but has now been idle for a number of years. It consists of a stratum 10 ft. 
thick, carrying 7-12 per cent of very soft asphalt. A number of seepages are in 
evidence along the side walls of the quarry and since the asphalt contains a large 
proportion volatile matter, they soon harden on exposure to the weather. Some 
of the seepages examined by Richardson contained 30 to 65 per cent of mineral 
matter, the extracted asphalt showing a penetration of between 35 and 45 at 
77° F., and yielding 12 per cent of fixed carbon. 

Edmonson County. Eldridge reports one deposit of asphaltic sand- 
stone 2 miles northwest of Bee Spring, and another 1| miles to the south. 
At the present time the only deposit in the State of Kentucky worked 
to any extent, occurs about 10 miles west of the celebrated Mammoth 

1 "Occurrences of Petroleum, Natural Gas, and Asphalt Rock in Western Kentucky," by 
Edward Orton, Geological Survey of Kentucky, 1891; "The Asphalt and Bituminous Rock De- 
posits of the United States," by George H. Eldridge, 22d Annual Report, U. S. Geol. Survey, 
Wash., D. C, Part I, p. 240, 1901. 

92 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 93 

Cave, near Brownsville.^ It consists of a stratum of fine sand impregnated 
with 8 to 10 per cent of asphalt, occurring in irregular beds 5 to 20 ft. thick. 
The rock asphalt is removed from an open quarry and first run through 
a crusher, then through a set of rolls to disintegrate it into small grains. 
It is used largely for paving purposes and is said to give excellent 
results. 

Warren County. Several deposits of sand asphalt are located at Youngs Ferry 
on the Green River, 12 miles north of the town of BowHng Green. One occurs in 
a bed about 10 ft. thick, and carries between 6 and 9 per cent of asphalt. A 
second consists of a vein 5 to 15 ft. thick containing about the same percentage 
of asphalt. Both are undeveloped. The extracted asphalt shows a penetration at 
77° F. of 200, and much volatile matter (13 per cent at 400° F. in seven hours). 

Logan County. A quarry has been opened up about 5 miles northeast of Rus- 
sell ville, exposing about 15 ft. of asphaltic sandstone in a bed about 100 ft. long. 
The rock carries about 7 per cent of asphalt, which shows very much less volatile 
matter than the preceding (about 4 per cent loss at 400° F. in seven hours). This 
mine is no longer active. 

Missouri 

Lafayette County. A bed of asphaltic sand occurs 1^ miles northwest of Hig- 
ginsville, carrying 8| per cent of asphalt, associated with sandy shale. This deposit 
has not been worked commercially. 

Indiana 

While drilling for oil at Princeton, a bed of asphalt several feet thick was 

found 100 ft. below a vein of coal. Seepages of liquid asphalt have also been 

reported in a well in the neighborhood. None of these have been developed. ^ 

Oklahoma 

This state is one of the richest asphalt-bearing centers in the United 
States. Asphalts are found in both the liquid and solid forms, occurring 
as springs, seepages and rock impregnations. Practically all the deposits 
are found in the southern portion of the state, between the 35th parallel 
of north latitude, and the Red River on the south, and included between 
the Arkansas line on the east, to the city of Granite, Oklahoma, on the west. 
This area is shown in Fig. 30, and includes deposits or prospects in the 
following counties: 

Comanche, Jefferson, Stephens, Garvin, Carter, Murray, Love, 
Marshal, Johnston, Pontotoc, Atoka, McCurtain and Leflore. 

1 M. H. Crump, /. Royal Soc. Arts, 69, 566, 1911. 

2 " Contributions to p:conomic Geology, 1902," Bulletin No. 213, U. S. Geol. Survey, Wash., 
D. C, p. 333, 1903. 



94 



ASPHALTS AND ALLIED SUBSTANCES 



The deposits consist of asphaltic sands, asphaltic limestone, mixtures 
of the two, and rarely asphalt impregnated shale. The principal occur- 
rences are included in Table XXIII. ^ 

In the majority of cases the asphaltic impregnation is of Uquid to 
semi-Hquid consistency, having a comparatively low fusing-point. It 
is contended by some authorities that the vast deposits of sand asphalt 
previously constituted oil-sands which have been laid bare by the agencies 
of erosion, faulting, crumpHng and upturning of the strata, so that the 

Asphalt. 




g Aspha/fArea, 
51 Asp/iaH- Beefs 



Fig. 30. — Map of Asphalt Region in Oklahoma. 



lighter oils and gases have escaped into the air, leaving the sand impreg- 
nated with the comparatively non-volatile asphaltic constituents. Most 
of the deposits occur along pronounced fault lines, although faulting is 
not essential, since certain deposits have become impregnated by the upris- 
ing of asphalt-bearing petroleum from regions below, through the porous 
sandstone or limestone. 

A characteristic feature of these deposits is the sand grains which 
are round and unconsolidated, being held together by the asphalt fiUing 
the voids. When the asphalt is extracted the grains fall apart, and show 
the same general characteristics as an ordinary petroleum-bearing sand. 



^ " Asphalt and Petroleum in Oklahoma. 
Guthrie, Okla., Mar. 1911. 



by L. L. Hutchison, Bull. 2, Okla. Geol. Survey, 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 95 



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NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 97 



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NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 



99 



The extent of these deposits has been variously estimated frOni 2 to 
13 miUion tons.^ 

Most of the asphalt mined in Oklahoma has been used for paving 
purposes, and the author has seen many satisfactory pavements laid 
throughout the State which have excellently withstood the wear and tear 
of traffic, also exposure to the elements. It is generally necessary to modify 
the rock asphalts either by combining the products obtained from dif- 
ferent deposits, or by incorporating pure sand, until a proper balance is 
obtained between the asphalt and the mineral constituents. In general, 
the best results have been obtained with mixtures containing 7 to 10 
per cent of asphalt in the finished paving composition. 

Numerous water extraction plants have been erected to separate the asphalt 
from the sand, but most of these have proven unsuccessful, since the extraction 
process raises the price of the refined asphalt so that it is unable to compete with 
petroleum asphalts obtained from other sources in the neighborhood. 

Tests made with sand asphalt taken from the quarry in Carter County, Sec. 
12 and N ^ Sec. 13, T 3 S, R 2 W, 18 miles northwest of Ardmore, indicated the 
following. The dry sand asphalt contained 12.5 per cent of pure asphalt having a 
fusing-point (K. and S. method) between 65 and 69° F. On subjecting it to the 
water extraction process, the following results were recorded: 





Products 
Recovered, 
Per Cent. 


Asphalt 
Content, 
Per Cent. 


Total Pure 
Asphalt, 
Per Cent. 




6 

3 

91 


95 
60 

2i 


5.7 


ImDure asphaltic residue 


1 8 




2.3 




2.7 






Asphalt in crude rock 






12 5 






Total 


100 











On boiling the crude rock with water, impure asphalt rises to the surface, and 
the "sand waste" settles to the bottom. Upon dehydrating the impure asphalt, 
more sand settles out, constituting what is designated "Impure Asphaltic Residue." 
The pure asphalt drawn off from this residue is termed "Asphalt Recovered." 

The "Asphalt Recovered" contained 5 per cent of mineral matter and tested 
as follows: 

(Test 9c) Consistency at 32° F 10 . 

Consistency at 77° F 1.5 

Con.sistency at 115° F 0.0 

(Test 9(f) Susceptibility factor 15 

(Test 15o) Fusing-point (K. and S. method) 65-69° F. 

(Test 16) Volatile at 500° F. in 4 hrs 10% 

i"Rock Asphalts of Oklahoma and Their Use in Paving," by L. C. Snider, Petroleum, 9, 
974, 1914. 



100 



ASPHALTS AND ALLIED SUBSTANCES 



Examination of Residue (from Test 16) 

(Test 9c) Consistency at 32° F 72.6 

Consistency at 77° F 10 . 7 

Consistency at 115° F 1.1 

(Test 9d) Susceptibility factor 63 . 1 

(Test lOfe) Ductility at 77° F Over 100 

(Test 15a) Fusing point (K. and S. method) 115° F. 

Upon evaporating the "Asphalt Recovered" at 250-260° C, the following figures 
were recorded: 



Total Loss, Per Cent. 


Fusing-point. 


Hardness at 77° F. 


15 
20 
25 

27 


120 
125 
147 
165 


14.0 
25.0 
36.3 
51.3 



A sample of the "Asphalt Recovered" upon being blown with dry air at 300° 
C. for nine hours, lost 23 per cent in weight, showed a fusing -point of 165° F., 
and a hardness at 77° F. of 48.0. It is apparent that the extracted asphalt is 
Scarcely affected by blowing, and thus differs from asphalts obtained upon dis- 
tilling petroleum. This is further corroborated by the author's observations on 
paints made fiom the extracted sand asphalt, which were found to be highly resist- 
ant to atmospheric oxidation. A sample spread on cloth and exposed to air indoors 
for about a year, showed scarcely any diminution in tackiness. Petroleum asphalts 
of the same consistency when tested in a similar manner, dry out in a much 
shorter time. • 

A mixture containing 82 per cent of the "Asphalt Recovered" fluxed with 18 
per cent of gTahanjite, showing the same fusing-point (165° F.), tested as follows: 

(Test 7) Specific gravity at 77° F 1 . 09 

(Test 9c) Consistency at 115° F 14.7 

Consistency at 77° F 27 . 1 

Consistency at 52° F 65.4 

(Test 9d) Susceptibility factor 30 . 7 

(Test 106) Ductility at 115° F 4.5 

Ductility at 77° F 1.0 

Ductility at 32° F 0.0 

(Test 11) Tensile strength at 115° F 1.8 

Tensile strength at 77° F 6.5 

Tensile strength at 32° F 9.5 

(Test 15o) Fusing-point (K. and S. method) 165° F. 

(Test 16) Volatile at 500° F. in 4 hrs 0.5% 

Louisiana. 

Lafayette Parish. A sand asphalt deposit has recently attracted attention about 
5 miles from Lafayette, covering about 50 acres on the surface.^ 

Texas. 

Montague County. Deposits are reported 3 to 3^ miles northeast of the City 
of St. Jo, carrying between 5 and 11 per cent of asphalt, averaging in the neigh- 
borhood of 7 per cent, although the percentage varies in different locaUties. They 
I Manufacturers Rec, 71, 64, 1917, 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 101 

contain sandstone, or a mixture of sandstone and limestone, but are of no com- 
mercial importance. 

Burnet County. This occurrence is at Post Mountain near the town of Burnet, 
and consists of an asphaltic limestone, containing about 10 per cent of asphalt, 
of a very soft consistency (having a penetration of 20-250 at 77° F.). 

Uvalde County. The most important Texan deposits are found in the south- 
western part of this county, about 18 to 25 miles west of the city of Uvalde, in 
the region of the Anacacho Mountains. They consist of hmestone, carrying 10 
to 20 per cent of asphalt, averaging about 15 per cent. CrystalHne calcite is 
present, also numerous fossil remains of molluscs, indicating the asphalt to be of 
animal origin. The deposits have been traced for several miles, but their exact 
extent is not accurately known, A large quantity has been quarried, and from 
recent reports the deposit is still being operated. The impregnating asphalt is 
quite hard, showing a conchoidal fracture and brilliant lustre. It has a moderately 
high fusing-point, and analyzes: carbon 81 per cent, hydrogen 12 per cent, sulphur 
65 per cent, nitrogen | per cent; total 100 per cent. 

Other deposits of the same general character are found in the neighborhood. 
One 20 miles south-southwest of Uvalde and 5 miles south of the preceding quarry 
showed 12 per cent of asphalt with 17 per cent of fixed carbon. 

Anderson, Jasper, and Cooke Counties. Minor deposits are reported in these 
counties, but are of no commercial value. ^ 

Utah. 

Carbon County. A deposit of asphaltic limestone occurs at the head of the 
right-hand branch of Pie Fork, a canyon northwest of the town of Clear Creek. 
The rock is non-uniform in composition, some containing between 6 and 14 per 
cent of asphalt (having a penetration at 77° F. of 7 to 15), and some as high as 
75 per cent (showing a penetration of 45 at 77° F.) with scarcely any fixed carbon. 

Utah County. A large area underlaid with asphaltic limestone occurs just north 
of Colton, and south of Strawberry Creek, extending from Antelope Creek on the 
east to Thistle on thj west. The principal deposit is at the town of Asphalt. 
No analyses are available. 

Grand County. At the head of the West Water Canyon about 20 miles north 
of the town of West Water, there is an asphaltic limestone deposit containing 
50 per cent asphalt and 50 per cent limestone. Investigations indicate that this 
asphalt is a progenitor of gilsonite. The extracted asphalt is reported by Rich- 
ardson to test as follows: 

(Test 7) Specific gravity at 77° F 1 . 037 

(Test 96) Penetration at 77° F 22 

(Test 16) Volatile at 212° F, 1 hr 2.8% 

(Test 19) Fixed carbon 8.0% 

(Test 23) Soluble in 88° naphtha ' 88 . 7% 

Uinta County. The largest deposit of asphaltic sandstone occurs southeast of 
Vernal, north of the White River, between the Ashley and Uinta Valleys, in a 
vein 3 to 16 ft. wide.^ It contains in the neighborhood of 11^ per cent asphalt. 

Another deposit, or rather a series of deposits, occurs in Argyle Creek, a trib- 

^"A Contribution to the Chemistry of Some of the Asphalt Rocks Found in Texas," by 
H. W. Harper; University of Texas Mineral Survey No. 3, May, 1902. 
> Wigglesworth, Trans. Am. Inst. Mining Eng., 17, 115, 1888. 



102 ASPHALTS AND ALLIED SUBSTANCES 

utary of the Minnie Maud Creek, which in turn flows into the Green River about 
20 miles south of Ouray. The material consists of an asphaltic sandstone, exploited 
under the name ''Argulite," carrying between 8 and 10 per cent of asphalt. The 
extracted asphalt tests as follows: 

(Test 5) Lustre Bright 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 0.997-1.013 

(Test 96) Penetration at 77° F 14° 

(Test lod) Temperature at which it flows 140° F. 

(Test 16) Volatile at 325° F. in 7 hrs 25 . 8% 

(Test 19) Fixed carbon 8.55% 

(Test 23) Soluble in 88° naphtha 88% 

(Test 26) Carbon 89 . 9% 

(Test 27) Hydrogen 9.0% 

(Test 28) Sulphur 0.0% 

(Tests 29 and 30) Nitrogen and oxygen 1-1% 

Total 100.0% 

(Test 34) Saturated hydrocarbons 25.0% 

Utah County. A sand asphalt deposit occurs about 1^ miles from Thistle, 
carrying 12 per cent of asphalt. This has been operated to but a small extent. 

Carbon County. Deposits of bituminous sand have been reported 8 miles from 
Sunnyside on the tributaries of Whitmore Canyon, carrying 11 per cent of very 
soft asphalt. The extracted asphalt tests as follows: 

(Test 16) Volatile at 325° F., 7 hrs 6.6% 

(Test 19) Fixed carbon 5.0% 

(Test 23) Soluble in 88° naphtha 81.8% 

California 

Mendocino County. Deposits of asphaltic sand are found 2 miles north of the 
town of Point Arena and | mile from the coast, carrying between 6 and 7 per 
cent of asphalt. A similar deposit occurs just north of Port Gulch. 

Santa Cruz County. Large deposits of asphalt sand occur 4 to 6 miles north- 
west of the city of Santa Cruz, near the summit of Empire Ridge, a spur of the 
Santa Cruz Mountains, 3| miles from the coast. A number of quarries have been 
opened up in this region, and the product used for constructing pavements in 
Santa Cruz and San Francisco. The rock contains between 10 and 17^ per cent 
of a very soft asphalt with a substantial proportion of volatile matter. The veins 
vary from 2 to 30 ft. in thickness, as shown in Figs. 31 and 32. 

Monterey County. Several deposits of asphaltic sandstone are scattered through- 
out the Salinas Valley. A prospect occurs about 10 miles from King City, com- 
posed of particles of quartz, feldspar and mica, impregnated with a varying per- 
centage of asphalt. Another deposit occurs 7 miles southeast of Metz at the head 
of Chelone Creek, of the same general character. A large vein, about 125 ft. 
thick and 3 miles long, has been reported near San Ardo, composed of <;oarse 
quartz grains, and a little feldspar, impregnated with a small percentage of asphalt. 

San Luis Obispo County. Sand asphalt deposits occur about 80 miles south- 
west of the town of San Luis Obispo, consisting of a number of actively worked 
quarries. The rock is jfine grained, of even texture, consisting mostly of quartz, 
with a small quantity of feldspar. The percentage of asphalt varies from 8 to 
18 per cent, averaging about 10. 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 103 

Santa Barbara County. Santa Maria Region. Associated with the pure asphalt 
deposit described on page 84, zones of asphalt-impregnated shale have been reported 
on the western slope of the Azufre Hills, containing 30 to 40 per cent of asphalt. 

Sisquoc Region. Deposits of sand asphalt occur in the neighborhood of the 
town of Sisquoc, carrying between 14 and 18 per cent of asphalt. The largest 
vein occurs in Bishop's Gulch, about 100 ft. thick, running fairly uniform in com- 



1 




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Fig. 31. — Sand Asphalt Quarries in Santa Cruz County, Cal. 



position. Some time ago an attempt was made to rem.ove the asphalt by extraction 
with solvents, but the process proved too costly and had to be abandoned. Similar 
deposits are found in the neighborhood of La Brea Creek, where a vein of sand 
asphalt occurs 20 to 60 ft. thick; also at Los Alamos Creek. 

Gaviota Region. A prospect has been reported in this locality consisting of a 
bed of sandstone and conglomerate about 25 ft. thick, containing 7 to 8 per cent 
of asphalt. 

Mores' Landing. This deposit is found on the seacoast about 7 miles west of 
Santa Barbara, occurring as veins and irregular masses in massive sandstone cliffs, 



104 



ASPHALTS AND ALLIED SUBSTANCES 



at least 100 ft. thick. According to Eldridge it contains 30 to 60 per cent of 
asphalt and has a strong resemblance in structure, brilliancy, and fracture to 
gilsonite, although it is very much softer in consistency. 

La Patera Region. A vein of asphalt of historical interest only, occurs about 
10 miles west of Santa Barbara, close to the coast. It varies in width from 2 to. 
12 ft., with a number of lateral branches several inches thick. The asphalt is 
associated with 30 to 50 per cent of mineral matter composed of shale, sand, and 




Fig. 32. — Sand Asphalt Quarries in Santa Cruz County, Cal. 

clay. It is stated that 30,000 tons have been removed from this mine, testing, 
when dried, as follows:-^ 



(Test 4) Fracture Irregular 

(Test 5) Lustre Dull 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1 . 38 

(Test 9a) Hardness on Moh's scale 2 

(Test 9b) Penetration at 77° F 

(Test 15rf) Temperature at which it flows 300° F. 

(Test 16) Volatile at 400° F., 7 hrs 2.5% 

(Test 19) Fixed carbon 14.9% 

(Test 21a) Soluble in carbon disulphide Approx. 50% 

(Test 21c) Free mineral matter About 50% 

(Test 23) Soluble in 88° naphtha 21 . 6% 

(Test 28) Sulphur 6.2% 

(Test 34) Saturated hydrocarbons 8.1% 

1 " The Modern Asphalt Pavement," loc. cit., p. 201. 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 105 

Carpinteria Region. This deposit composed of asphaltic sand about 15 ft., thick, 
lying along the ocean's shore, is illustrated in Fig. 33. It contains 18 to 20 per 
cent of asphalt filling the interstices of unconsolidated quartz grains. Some time 
ago a process was installed for extracting the asphalt with water, but this never 
proved successful commercially. 

Orange County. Bituminous sands have been reported 4 miles southwest of 
Chino, in a layer about 6 ft. thick, containing varying percentages of asphalt. 




Fig. 33. — Asphaltic Sand on the Shore at Carpenteria, Cal. 

Canada 
Alberta 

McMurray Region. Vast deposits of asphaltic sands occur on both banks of 
the Athabaska River, and its tributary, the Clear Water River, covering probably 
not less than 750 square miles. ^ A characteristic view of the outcrop on the Atha- 
baska River is shown in Fig. 34 {A and 5). 

These sands contain about 19 per cent of asphalt, which is amenable to the 
water-extraction process. A specimen of the extracted asphalt examined by the 
author tested as follows: 

(Test 7) Specific gravity at 77° F 1 . 022 

(Test 96) Penetration at 77° F Too soft 

for test 

(Test 9c) Consistometer hardness at 115° F 0.0 

Cousistometer hardness at 77° F 0.0 

Consistometer hardness at 32° F 2.7 

> "Bituminous Sands of Northern Alberta," by S. C. Ells, Dept. of Mines, Ottawa, Canada, 
1914. 



106 



ASPHALTS AND ALLIED SUBSTANCES 



(Test 106) Ductility at 115° F 2.0 

Ductility at 77° F 7.0 

Ductility at 32° F 12.5 

(Test 15a) Fusing-point (K. and S. method) 50° F. 

(Test 16) Volatile at 500° F. in 4 hrs 17.9% 

(Test 19) Fixed carbon 10.55% 

(Test 21o) Soluble in carbon disulphide 97. 3% 

(Test 21c) Free mineral matter 2.7% 



>-%^ 





(A) 




(B) 

Courtesy of S. C. Ells. 

Fig. 34. — Asphaltic Sand on Banks of Athabaska River, Alberta, Can. 
The non-volatile matter tested as follows: 

(Test 7) Specific gravity at 77° F 1 . 028 

(Test 96) Penetration at 77° F 52 

(Test 9c) Consistency at 115° F 3.7 

Consistency at 77° F 8.5 

Consistency at 32° F 49 . 3 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 107 

(Test 9d) Susceptibility factor 36 . 5 

(Test 106) Ductility at 115° F 34.5 

Ductility at 77° F 45.0 

Ductility at 32° F 0.5 

(Test 11) Tensile strength at 115° F 0.3 

Tensile strength at 77° F 1.5 

Tensile strength at 32° F 25 . 5 

(Test 15a) Fusing-temperature (K. and S. method) 125° F. 

(Test 19) Fixed carbon 12 . 33% 

The crude asphalt, after being tempered with additional pure sand to reduce 
the percentage of asphalt, has given successful results for paving purposes in Ed- 
monton, Canada. 

Mexico 

Several deposits of sand asphalt have been reported in the neighborhood of 
Tampico and Vera Cruz, containing 8 to 14 per cent of asphalt, but none have 
been developed commercially. 

Cuba 

Province of Matanzas. Semi-solid asphalts have been mined for many years 
at the bottom of Cardenas Harbor. The most important deposit, known as the 
Constancia Mine, occurs about 12 ft. below the level of the water, and is conse- 
quently mined with difficulty. Other deposits of semi-liquid asphalt containing 
more or less mineral matter, occur at the mouth of the La Palma River, about 20 
miles from Cardenas; also near Sabanillo de la Palma, about 30 miles east of 
Cardenas and 4 to 5 miles west of Hato Nuevo. Analyses are not available. 

Province of Pinar del Rio. Deposits of sand asphalt have been reported at 
Bahia Honda and Mariel, in the neighborhood of Mariel Bay, also at Vuelta 
Abajo. No analyses are available. 

Province of Havana. An extensive deposit known as the "Angelo Elmira 
Mine," has been found near Bejucal, about 18 miles south of Havana, associated 
with mineral matter composed of calcium carbonate, silica, and silicates, which, 
according to Richardson,^ tests as follows: 

(Test 1) Color in mass Black 

(Test 4) ' Fracture , Semi-conchoidal 

(Test 5) Lustre Dull 

(Test 6) Streak Reddish brown 

to brown 

(Test 7) Specific gravity at 77° F 1 . 30-1 . 35 

(Test 9a) Hardness, Moh's scale 2 

(Test 96) Hardness, penetrometer at 77° F 

(Test 15d) Temperature at which it flows 240-270°- F. 

(Test 16) Volatile at 325° F., 7 hrs. (dry substance) About 1% 

Volatile at 400° F., 7 hrs. (dry substance) About 1^% 

(Test 19) Fixed carbon 17.4-25.0% 

(Test 21a) Soluble in carbon disulphide 70 -75% 

(Test 21c) Free mineral matter (calcium carbonate, etc.) 21 -28% 

(Test 23) Soluble in 88° naphtha 32 -50% 

(Test 28) Sulphur About 8.3% 

Province of Camaguey. Impure soft and hard asphalt deposits are found near 
Minas, a small town between Camaguey and Nuevitas. 

1 "The Modern Asphalt Pavement," loc. cit., p. 195. 



108 ASPHALTS AND ALLIED SUBSTANCES 

SOUTH AMERICA 

Trinidad 
St. Patrick County. 

One of the largest deposits of asphalt in the entire world occurs on the 
Island of Trinidad^ on the north coast of South America, situated a short 
distance from the mainland of Venezuela, between the Caribbean Sea 
on the west and the Atlantic Ocean on the east. 

Small deposits are scattered all over the Island, but the largest one 
known as the *' Trinidad Asphalt Lake," is situated on La Brea Point, 
in the Wards of La Brea and Guapo, on the western shore. The lake 
is situated on the highest part of La Brea Point, 138 ft. above sea level. 
It covers an area nearly circular comprising 115 acres, in a slight depression 
or shallow crater at the crest of the hill. The exact location of the lake 
is shown in Fig. 35. The lake measures about 2000 ft. across and over 
135 ft. deep in the centre, becoming shallower towards the edges. A 
panoramic view is shown in Fig. 36. 

The asphalt surface is broken up into a series of large folds with accu- 
mulations of rain water in the creases. A typical view is shown in Fig. 37. 
The entire mass of asphalt is in constant but slow motion from the centre 
towards the edges, probably due to the continual influx of solid material 
at the centre, accompanied by a strong evolution of gas which imparts 
a porous or honeycombed structure. The evolution of gas through the 
water is shown in Fig. 38. Wherever a hole is dug in the surface, it slowly 
fills up and disappears. The asphalt is softest in the centre of the deposit, 
and gradually hardens towards the circumference. Even in the centre, 
the consistency is such that it will bear the weight of a man, and can be 
readily broken out in large masses with picks as shown in Fig. 39. 

Shrubs and small trees grow on the surface in isolated patches known 
as " islands," which slowly migrate from place to place with the move- 
ment of the asphalt. Grassy vegetation extends along the edges of the 
lake merging into the surrounding country. 

The crude asphalt is loaded on small cars run by cable over the lake 
in a loop, the rails being supported by wooden ties which must be replaced 

1 Report of the Inspector of Asphalt and Cement, Engineering Department, District of Columbia, 
Wash., D. C, 1892: "On the Nature and Origin of Asphalt," published by the Barber Asphalt Pav- 
ing Co., Long Island City, N. Y., Oct., 1898: "The Modern Asphalt Pavement," by Clifford Rich- 
ardson, 1908, p. 176 et seq.: "Trinidad and Bermudez Lake Asphalt and Their Use in Highway 
Construction," by Clifford Richardson (pamphlet): "The Wonderland of Trinidad," issued by the 
Barber Asphalt Paving Co. (pamphlet): "An Examination of Some Bituminous Mineials," by 
F. C. Garrett, J. Soc. Chem. Ind., 31, 314, 1912; "The Proximate Composition and Physical 
Structure of Trinidad Asphalt," by Clifford Richardson, Proc. Am. Soc. Testing Materials, 
6, 509, 1906; "Studies in Asphalt," by C. J. Frankforter, J. Ind. Eng. Chem., 2, 239, 1910; "The 
Hydrocarbons of Utah," by Bardwell, et al., J. Ind. Eng. Chem., 6, 973, 1913; also 6, 865, 1914, 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 109 

from time to time as they gradually sink into the surface of the asphalt. 
The asphalt is transferred to an inclined cable way at the end of the loop 
which runs to the shore, and thence to a long pier where it is dumped 
on board steamers. (Fig. 40.) 

It has been estimated that the lake contains over 9 million tons of 
asphalt. Although vast quantities have been removed in the past, the 




Fig. 35. — Map of Trinidad Asphalt Lake. 



level of the lake has not sunk more than 8 to 10 ft. since the rate of 
influx closely approximates the quantity removed. 

The fresh material consists of an emulsion of asphalt, gas, water, 
sand and clay. According to Richardson^ oil sands occurring at a depth 

»"A Unique Geophysical Phenomenon, Trinidad Asphalt, Interesting from the View of Dispersoid 
Chemistry," J. Phys. Chem. 19, 241, 1915; " The Nature and Origin of Petroleum and Asphalt," by 
CUfford Richardson, Met. Chem. Eng. 16, 3, 1917; Eng. Chem. 8, 4, 1916. 



110 



ASPHALTS AND ALLIED SUBSTANCES 




I 



I i 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 111 




Courtesy of Barber Asphalt Paving Co. 
Fig. 37. — Folds in the Surface of Trinidad Lake. 




w-^m^^mr^'' 



Courtesy of Barber Asphalt Paving Co. 

Fig. 38.— Evolution of Gas from Trinidad Lake. 



112 



ASPHALTS AND ALLIED SUBSTANCES 



carry an asphaltic petroleum and natural gas under high pressure, which 
on coming in contact with a paste of colloidal clay and siHca are converted 
into the asphalt which emerges at the surface. (See page 55.) 




Courtesy of Barber Asphalt Paving Co. 
Fig. 39. — Gathering Trinidad Lake Asphalt. 



A ^ 



-V * 







FiQ. 40.- 



Courteay of Barber Asphalt Paving Co. 
-Transporting Trinidad Lake Asphalt. 



The crude Trinidad lake asphalt is extremely uniform in composition, 
as is evident from analyses of samples taken from different points over 
the surface, calculated on a water- and gas-free basis. 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 113 

The crude material, when freshly sampled at the centre of the lake 
is composed of: 

Water and gas volatilixed at 100° C 29 . 0% 

Asphalt soluble in carbon disulphide 39 . 0% 

Asphalt absorbed by mineral matter 0.3% 

Mineral matter on ignition with tricalcium-phosphate 27.2% 

Water of hydration in mineral matter 4 . 3% 

Total 99.8% 

Specimens taken from various portions of the lake's surface, after 
pulverizing and drying to constant weight in air at room temperature, 
appear fairly uniform in composition, averaging: 

Soluble in carbon disulphide 55 . 0% 

Free mineral matter 35 . 5% 

Water of hydration, etc 9.7% 

The so-called '' Water of hydration, etc." includes water chemically 
combined with the clay, asphalt absorbed by the clay and not remov- 
able by carbon disulphide and the inorganic salts which are volatilized 
on ignition upon determining the mineral matter. 

The emulsified water contains mineral constituents in solution to 
the extent of 82.1 grams (at 110° C.) per kilo, composed largely of sodium 
chloride. The gas is a mixture of methane, carbon dioxide, hydrogen 
and hydrogen sulphide. The mineral matter consists of extremely finely 
divided silica and colloidal clay. 

The crude asphalt is subjected to a refining process by heating it to 
160° C. to drive off the water. A small amount of volatile matter is also 
removed during this treatment. The refined asphalt tests as follows: 

(Test 1) Color in mass Black 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Dull 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1,40-1.42 

(Test 9a) Hardness, Moh's scale 1 -2 

(Test 9b) Penetration at 115° F 10 -15 

Penetration at 77° F 1.5-4.0 

Penetration at 32° F , 0.25-0.75 

(Test 9c) Consistency at 115° F 32.7 

Consistency at 77° F 74 . 9 

Consistency at 32° F Above 100 

(Test 9d) Susceptibility factor Greater than 80 

(Test 10a) Ductility (Dow Method): 

At 115° F 8.0 

At 77° F 1.8 

At 32° F 0.1 

(Teat 10b) Ductility (Author's Method): 

At 115° F 1.5 

At 77° F 1.0 

At 32° F 0.0 



114 ASPHALTS AND ALLIED SUBSTANCES 

Test 11) Tensile strength (Author's Method): 

At 115° F 4.15 

At 77° F 21.0 

At 32° F 27.0 

(Test 14a) Behavior on heating: 

At 0° C Brittle, crumbled rather easily 

From 5 to 10° C Slightly brittle, not "crumbly" 

From 20 to 25° C . Less brittle, not "crumbly" 

From 45 to 50° C No apparent change 

From 65 to 70° C Begins to soften 

From 102 to 108° C Entirely melted 

From 120 to 125° C Consistency of molasses, ap- 
peared stringy or fibrous 
when stirred 

From 150 to 155° C Slightly mobile 

From 170 to 175° C Very mobile 

From 208 to 210° C Flashes 

From 233 to 235° C Burns 

(Test 15a) Fusing-point refined asphalt (K. and S. 

method) 188° F, 

(Test 15a) Fusing-point, pure asphpJt extracted from 

mineral matter 131|° F. 

(Test 15d) Temperature at which it flows 190° F. 

(Test 16) Volatile at 325° F., in 7 hrs 1.1-1.7% 

Volatile at 400° F., in 7 hrs 4 . 0- 5 . 25 

(Test 19) Fixed carbon 10.8-12.0% 

(Test 20) Distillation test: 

0-150° C 14.93% 

150-200° C 10.42% 

200-250° C 2.26% 

Coke and ash 72 . 39%, 



Total 100.00%, 

(Test 21) Soluble in carbon disulphide 56-57% 

Asphalt retained by mineral matter 0.3% 

Mineral matter on ignition with tricalcium- 

phosphate 38 . 5% 

Water of hydration (clay and silicates) 4.2% 

(Test 22) Carbenes 0.0-1.3% 

(Test 23) Soluble in 88° naphtha (pure asphalt) 62-64% 

(Test 24) Grams crude dry material soluble in 100 
grams cold solvent: 

Amyl acetate 132 

Amyl alcohol. Insoluble 

Amyl nitrate 84 

Aniline 3 

Benzol 48 

Carbon disulphide In all proportions 

Carbon tetrachloride In all proportions 

Chloroform 10 

Ethyl acetate ' 30 

Ethyl alcohol Insoluble 

Ethyl ether 109 

Nitrobenzene 39 

Propyl alcohol Insoluble 

Toluol 39 

Turpentine 115 

Solubility of pure asphalt upon extraction 
cold by: 

Acetone 21 . 7% 

Benzol 99.9% 

Chloroform 93 . 4% 

Ethyl ether 68 . 9% 



NATIVE ASPHALTS ASSOCIATED AMTH MINERAL MATTER 115 

(Test 26) Carbon 80-82% 

(Test 27) Hydrogen 10-11% 

(Test 28) Sulphur 6-8% 

(Test 29) Nitrogen 0.5-0.8% 

(Test 33) Paraffine 0.0% 

(Test 34) Saturated hydrocarbons 24.4% 

(Test 37d) Saponification value 40.0 

(Test 38a) Free asphaltous acids 6.4% 

(Test 386) Asphaltous acid anhydrides 3.9% 

(Test 38c) Asphaltenes 37 . 0% 

(Test 38d) Asphaltic resins 23 . 0%, 

(Test 38e) Oily constituents 31.0% 

So-called Trinidad " land asphalt " represents material which over- 
flows from the lake at its edges, where it has been exposed to the action 
of the weather for centuries. It is derived from the same source as the 
lake asphalt, and has the same general physical and chemical character- 
istics. It is knowm under various names; lor example: " cheese pitch " 
is a variety which resembles the lake asphalt most closely with respect 
to its containing gas cavities; ''iron pitch" is a variety which has 
hardened on exposure to the weather to such a degree that it resembles 
refined lake asphalt; " cokey pitch " is a variety which has been coked 
or carbonized by brush fires, etc. 

The land asphalt varies in its composition from place to place, but differs 
from the lake asphalt in the following respects: 

(1) It contains Httle to no gas or water. 

(2) It contains a slightly higher percentage of mineral matter (from 1 to 2 
per cent). 

(3) More of the volatile ingredients have been evaporated. 

These influence the tests as follows: 

The specific gravity is somewhat higher (up to 1.45). 

The hardness is greater. 

The fusing- and flowing-points are higher (between 30 and 40° F.). 

The volatile matter is less (about 1 per cent). 

The percentage of fixed carbon is slightly higher (about 2 per cent). 

The following table shows the quantity of asphalt produced during the years 
1912-1916, in long tons: 

TABLE XXIV 



Year 


To United States. 


To Europe. 


To other Countries. 


Grand 




Lake. 


Land. 


Total. 


Lake. 


Land. 


Total. 


Lake. 


Land. 


Total. 


total. 


1912 

1913 


95,111 
123,873 

67,357 
118,001 
117,719 


8; 600 
1,400 
2,950 
1,250 


103,711 
125,273 
70,307 
119,251 
117,719 


85,299 
104,153 
75,297 
18,025 
13,380 




85,299 
104,153 
75,297 
18,025 
13,380 


486 
605 




486 

co,- 


189,496 
230 031 


1914 




145 604 


1915 








136,026 


1916 








131,099 













116 ASPHALTS AND ALLIED SUBSTANCES 

Argentine 

Province of Jujuy. An asphalt lake, known as the "Laguna de la Brea," 
occurs some distance northeast of the City of Jujuy. The asphalt is sulphurous, 
of a semi-liquid consistency which hardens at the edges. It is mixed with more or 
less earthy constituents. Seepages of mineral oil are also found locally. 

Province of Chubut. Deposits of soft, impure asphalt are reported in the vil- 
lage of Comodoro Rivadavia, associated with seepages of asphaltic petroleum. 
The asphalt has not been developed, and no analyses are available. 

EUROPE 

France 

Department of Landes. Near Bastennes, a moderately large-sized deposit of 
asphaltic sand is found, associated with fossil shells, indicating that this asphalt 
is of animal (marine) origin. These shells are distributed throughout the asphalt 
bed, which measures between 10 and 14 . ft. thick. On exposure to the air, the 
shells fall to pieces in a fine powder and the asphalt hardens materially, due to 
the loss of volatile matter. An analysis by L. Malo shows the material to contain: 
asphalt 38.45 per cent, calcium carbonate 4.96 per cent, and sand 56.59 per cent. 

Department of Gard. Very large deposits of rock asphalt occur in this Depart- 
ment, embracing in the north the Concessions of St. Jean-de-Maruejois, and in 
the south including the Concessions of Servas, Cauvas, Sumades and Puech. These 
have long been known and worked for many years. Deposits of lignite and coal 
occur in the same region. The asphalt is associated with limestone, sandstone and 
shale, and varies in percentage between 5 and 16 per cent. An average analysis 
shows it to contain: asphalt 10 to 12 per cent, clay 0.5 to 0.8 per cent, calcium 
carbonate 84-86 per cent, magnesium carbonate about 2 per cent, and moisture 
0.5 per cent. 

Department Haute-Savoie. Deposits of asphalt associated with limestone and 
sandstone occur at Mussieges, Frangy, Lovagny, Bourbonne, and Chavaroche, in 
strata between 13 and 16 ft. thick. An analysis of the rock asphalt mined at 
Chavaroche shows it to contain: asphalt 29.2 per cent, calcium carbonate 51.6 
per cent, and sand 19.2 per cent. This is used for paving purposes. 

Department of Ain. At BeHpgarde in the northern part of the Depart- 
ment occurs a deposit of asphaltic limestone unevenly impregnated with 
asphalt, and also associated in part with heavy petroleum oils. 

The well-known Seyssel deposits also occur in this Department at 
Pyrimont, Volant and Challonges, consisting of a fine-grained limestone 
impregnated with asphalt. This region is shown in Fig. 41. The deposits 
consist of a series of hillside quarries along the Rhone River. The 
asphaltic impregnation varies from 2 to 8 per cent as a maximum, the 
balance consisting almost exclusively of calcium carbonate. Fossil 
shells are frequently encountered, also crystalline calcite. The deposits 
at Pyrimont are now largely exhausted, after having been worked for 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 117 



many years. The Volant deposits are still being worked actively. 
According to L. Malo the asphalt extracted from the Seyssel deposits 
tests as follows: 

Water 1.9 - 0.0% 

Asphalt (Fusing-point, 87° F., K. and S. method) 8.00-8.15% 

Magnesium carbonate . 10% 

Calcium carbonate 89 . 55-91 . 30% 

Insoluble in acid 0.10- 0.45% 

Loss, etc 0.25% 





J 


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o 




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Fig. 41. — Map of Seyssel Asphalt Deposit, France. 

Switzerland 

Extensive deposits of asphalt impregnated limestone occur west 
of Neuchatel Lake, in the so-called Val de Travers region. These 



118 



ASPHALTS AND ALLIED SUBSTANCES 



have been exploited for many years and - marketed under the names 
" Neuchatel Asphalt" and '' Val de Travers Asphalt." The exact 
location of the region is shown in Fig. 42. The percentage of asphalt 
varies Considerably; thus, the " ordinary " grade contains about 10.7 
per cent of asphalt, the so-called " rich " grade contains 15.3 per cent of 
asphalt, the ''extra " grade 17.5 per cent and the " powder " 9.6 per cent. 
The average product contains: asphalt 10.15 per cent (fusing-point 
50° F., K. and S. method), calcium carbonate 88.4 per cent, iron and alumi- 
ninium oxides 0.25 per cent, magnesium carbonate 0.3 per cent, matter 
insoluble in acid 0.45 per cent, and loss 0.45 per cent. The theory has 




Fig. 42.— Map of .Neuchatel (Val-de-Travers) Asphalt Region, Switzerland. 

i j 
been advanced that these asphalts have been produced by the decom- 
position of marine animal and vegetable matters, which is borne out 
by the associated fossils. 

Smaller deposits occur at Auvernier, Bevaix, and St. Aubin, south of Neuchatel, 
on the western shore of Lake Neuchatel, containing smaller percentages of asphalt 
than the preceding. 

Alsace-Lorraine 



The deposits in this region occur in a well-defined area in the neighborhood 
of Lobsann a short distance north of Strassburg, as shown in Fig. 43. The 
asphalt strata have been traced 6 to 7 miles, extending through Sul^ u. Wald, 
Pechelbronn and Lampertsloch. They occur as asphalt-impregnated limestone and 
sandstone associated with lignite. Petroleum is also found loe^llly. The asphal- 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 119 

strata average about 80 ft, in thickness and carry many fossils. The region is 
badly faulted. The bituminous limestone has the following average composition: 

Asphalt (Fusing-point 77° F., K. and S. method) 11.9 -12.32% 

Calcium carbonate , 69 . -71 . 43% 

Iron and aluminium oxides 4.3 - 5.9% 

Sulphur 5.0-5.6% 

Magnesium carbonate 0.3% 

Silica 3.15-3. 65% 

Loss, etc 1.7 - 3 .4% 





Klimbach We.rsenburg^^ 




^^^^^^^^ A Altenstadt^ 




J^'-^^^Scb^UiOeeb^gJ^^^^ j 




/ 


^^^m"'"' >T 


/ 


y^^-^LOBSANN:--^^fc!«|keffenacy^ / 


Nehweiler / 


J^—;^^^:^^'^£^=^Lj=^ jgMg^elshofen / 


^S^hederbronn Vrojlhweiler 


>"••"- ^^hi^^^^gJ ^S/ nspach 


^^V .^^'''''^^^^''^^'^^ 


J ^^VfcHe'tschweiler-// 




Schacht Pechelbronn ^^^ 1 / / 


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KjiGundershofen 


/^ 


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^Hagenau 




^ 






^•Bischweiler 




STRASSBURG^=-= 




i 



Fig. 43. — Map of Lobsann Asphalt Region, Alsace-Lorraine. 

The asphaltic sandstone at Pechelbronn occurs in veins 3 to 6 ft. thick, con- 
taining a soft, viscous asphalt which, when extracted show^s a gravity between 
0.90 and 0.97 at 77° F. Large quantities of asphalt have been mined in this 
region for paving purposes. 

Germany 

Province of Hanover. At Limmer, as mall village near Ahlem in the 
plains of Acker, about 18 miles west of Hanover there occurs a deposit 
of asphaltic limestone measuring 1600 by 2250 ft. which has been worked 
for several hundred years. The vein has the general cross-section shown 
in Fig. 44, and is worked by open quarrying. ^ The rock carries between 
8 and 20 per cent of asphalt and contains numerous fossil shells. As 
freshly mined it has a brownish to gray-brown color, and the asphalt 



1 Where a represents alluvium; h 
nated limestone; e, shale; and /, limestone 



impregnated limestone; c, clay; d, asphalt-impreg- 



120 



ASPHALTS AND ALLIED SUBSTANCES 



impregnation is very soft in consistency, containing a large proportion of 
volatile constituents. The average analysis shows: 

Asphalt (Fusing-point 61*» F., K. and S. method) 13.4-14.3% 

Calcium carbonate 67% 

Iron and aluminium oxides, etc 17 . 5-19 . 5% 

Loss 0.3- 1.18% 

At Waltersberge, near Limmer, a very large deposit of asphaltic limestone is 
found, containing 5 to 7 per cent of asphalt. It is estimated that about 3,000,000 
tons occur in this deposit, but the material is so poor in asphalt that it must be 
enriched by mixing with Limmer or Trinidad asphalt. 




Fig. 44. — Cross-Section of Limmer Asphalt Deposit, Germany. 



At Holzen, a small village on the River Ith, a short distance north of Vorwohle, 
occurs a well known, and one of the most productive asphalt deposits in Germany. 
The asphalt stratum has been traced for approximately 14,500 ft. and forms a 
succession of layers 65 ft. thick carrying a variable percentage of asphalt asso- 
ciated with limestone, and separated with clay and shale. The rock asphalt analyzes 
as follows: 

Asphalt (Fusing-point 65-70*' F., K. and S. method) 5.4-8.5% 

Calcium carbonate 80 . -90 . 9% 

Iron and aluminium oxides 4.0 - 5.0% 

Silica 2.55- 4. 77% 

Loss 0. 15- 2. 11% 

A small deposit has been reported at Wintjeberg in this same neighborhood, 
but has not been worked to any extent. 

Province of Westphalia. Minor deposits have been found near the villages of 
Darfeld, Buldern, Hangenau, and Appelhiilsen, associated with clay and shale. 

Province of Hessen. At Mettenheim between Worms and Appenheim, occurs 
a deposit of asphaltic limestone and clay carrying a large quantity of fossil fish 
remains. The rock contains between 74.4 and 82.6 per cent of asphalt of a com- 
paratively high fusing-point. 

Austria 
Province of Dalmatia 

Vrgorac. A deposit of asphaltic limestone occurs at Vrgorac, having a specific 
gravity at 77° F. of 1.697 containing an average of 26 per cent of asphalt. Analyses 
show the following ingredients: 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 121 





Analysis 1, 
Per Cent. 


Analysis 2, 
Per Cent. 


Analysis 3, 
Per Cent. 


Asphalt 


2.94 

21.70 

7.12 


7.12 


38.92 


Silica 




Iron and aluminium oxides 


58.10 
1.10 










36.60 


61.08 




32.58 
0.97 












4.10 










Total 


100.00 


99.87 


100.00 







The first analysis represents an asphaltic Limestone containing silica, the second 
analysis represents an asphaltic shale, and the third an asphaltic limestone (pure). 
Considerable asphalt has been derived from this deposit for paving purposes. 

Asphaltic shales have been reported near the town of Skrip, on the Island 
of Brazza, situated near the coast of Austria, in the Adriatic Sea, containing between 
15 and 40 per cent of very soft asphalt. The layers are betweeh 2 and 4 ft. in 
thickness. There also occurs a deposit of asphaltic limestone containing about 13 
per cent of asphalt and 87 per cent of calcium carbonate, having a brownish-black 
color and containing a substantial proportion of volatile matter. 

At Morowitza near Sebenico, on the Adriatic Sea, occurs a deposit of asphaltic 
limestone carrjdng 10 to 15 per cent of asphalt, 95 per cent of calcium carbonate, 
and about 4 per cent of magnesium carbonate. 

At Porto Mandorlo, near the town of Trau on the Adriatic Sea, occur beds of 
crystalline limestone of a brownish color containing 9.2 per cent of asphalt and 
90.8 per cent of calcium carbonate. Further deposits have been located in thia 
region at Biskupija and Vinjisce. 

Province of Tyrol. A very peculiar asphaltic shale occurs at Seefeld, 5000 ft. 
above the sea-level, in beds several feet thick with numerous fossil fish remains, 
in between layers of dolomite. This deposit constitutes one of the main sources 
of supply of ichthyol, which is recovered upon subjecting the material to a process 
of destructive distillation in suitable retorts. The material best suited for thia 
purpose is composed of the following: 

Asphalt 26.41% 

Calcium and magnesium oarbonates 38 . 22% 

Clay 6 . 67% 

Silica 19.03% 

Iron oxide 5 . 95% 

Loss and moisture 3 . 72% 

Total 100.00% 

Province of Bihar 

Deposits of asphaltic sand occur at Tataros containing approximately 15 per 
cent of soft, sticky asphalt with a characteristic penetrating odor. It is found in 
strata between 6 and 25 ft. thick, 5000 ft. long and 4000 ft. wide. Large quan- 
tities of asphalt have been mined from this deposit, which constitutes one of the 
largest sources of supply in Austria. Analysis shows between 15 and 22 per cent 
asphalt, fusing at 83° F. (K. and S. method). The water-extraction process has 



122 ASPHALTS AND ALLIED SUBSTANCES 

been used to separate a semi-liquid asphalt from the sand, leaving a residue con- 
taining 3 per cent of asphalt which could not be separated. The pure, soft asphalt 
thus separated is distilled to recover the heavy oils and then converted into mastic 
by mixing with limestone. 

An asphaltic sand deposit associated with lignite is found a few miles northwest 
of Bodonos containing between 11 and 15 per cent of asphalt. 

A short distance east of Felso Derna there occurs a bed of sand asphalt, very 
similar in character and composition to that found at Tataros, carrying 15 to 
22 per cent of asphalt. The extracted asphalt contains 0.73 per cent of sulphur, 
5.4 per cent of ash, and 1.6 per cent of crystalhzable paraffine.^ 

Province of Herzegovina 

A deposit of asphaltic limestone occurs at the village of Popovo Polje, having 
a black to grayish-black color, and carrying between 16 to 20 per cent of asphalt. 
It contains a large percentage of volatile matter, which causes the crude material 
to ignite very readily and burn with a luminous flame. 

A little south of the village of Misljan, and east of the town of Popovo Polje, 
occurs another and larger deposit of asphaltic limestone 6 to 20 ft. thick. The 
asphaltic impregnation is sticky and semi-liquid, varying between 3 and 35 per 
cent. The richer varieties ignite readily and burn with a luminous, smoky flame. 

A deposit of asphaltic limestone about 100 ft. wide and 10 ft. thick occurs 
at Dra6evo, about 2^ miles east of the city of Metkovic. The rock is of a 
brownish black to dull black color, carrying 5.4 per cent of asphalt. It is not rich 
enough to be worked profitably. 

Italy 
Compartment of Marches 

Province of Pesaro ed Urbino. Impure, solid asphalt is found at Sant' Agata 
Feltria associated with sulphur, but is not mined actively. At Tallamello and 
Urbino, deposits of solid and semi-liquid asphalt occur associated with more or 
less sulphur. These are merely of interest from a geological standpoint. 

Compartment of Abruzzi ed Molise 

Province of Ahruzzo Citeriore. Minor occurrences have been reported at Tocco 
di Casauri, Valle San Leonardo, Sant' Ensemia a Majella, Ceramanico, Salle, Cir- 
condario di Lanziano and Palena. In the neighborhood of San Valentino, extensive 
deposits of asphaltic limestone have been worked in strata 2| to 3 miles long and 
about 100 ft. thick. Quarries have been opened up in the Valley of the Pescara 
River at the villages of Roccamorice, Abateggio, Manopello, Lettomanopello, 
Tocco, and Papoli. Three distinct zones are distinguished. The lower carries 
between 9 and 10 per cent of asphalt, the middle an average of 17 per cent, and 
the upper 9 to 30 per cent. In certain localities the asphalt has a rubbery con- 
sistency, and is deep black in color, and in others it is very soft and semi-liquid. 
The deposits are rich in fossil shells. Analyses show the following composition: 

Asphalt 10.62- 5.70% 

Silica 0.06- 0.48% 

Calcium carbonate 49 . 70-86 .40% 

Magnesium carbonate 1 . 20-32 .0% 

Iron and aluminium oxides 0.16- 1 . 18% 

Moisture . 22- . 98% 

»J. Marcusson, Chem. Rev. Fett-Harz-Ind., 19, 171, 1912. 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL IvIATTER 123 

Compartment of Calabria 

Province of Basilicata (Potenza). Asphaltic limestone deposits have been reported 
at Tamutola, Magliano, Setere and Leviano. 

Compartment of Campania 

Province Terra di Lavoro (Caserta). One of the largest asphalt quarries in the 
entire region, which, however, has not been very active in recent years, occurs at 
Colle San Magno. Analyses of the product as mined show it to be composed of 
the following: 

Asphalt 7 . 15% 

Calcium carbonate 73 . 7G% 

Calcium sulphate 1 . 72% 

Iron and aluminium oxides 3 . 02% 

Magnesium carbonate 14 . 24% 

Silica 0. 10% 

Similar deposits of asphaltic limestone occur at Liri, Frosinone, Monte San 
Giovanni, Banco, Castro dei Volsci and Fillettino. 

Compartment of Sicily. 

Province of Syracuse. The largest and most important Italian asphalt 
deposit occurs at Ragusa, about 13 miles from the southern coast of 
Sicily, on the River Irminio, in a bed 16 to 64 ft. thick, and 1600 to 2000 
ft. long. It contains variable percentages of asphalt, ranging from 2 
to 30 per cent, associated with a soft limestone composed largely of fossil 
shell remains. Two varieties of rock asphalt are mined — a brown variety 
relatively poor in asphalt, containing between 3 and 7 per cent, and a 
black variety carrying an average of 15 per cent. It has been worked for 
many years, and over 100,000 tons are mined annually for use on the 
continent of Europe, being marketed in the form of a powder especially 
suitable for compressed asphalt pavements. The material as mined 
requires no further treatment other than grinding. Analyses show the 
following compositions : 

Asphalt 8.80-14.05% 

Calcium carbonate 82.15-88.21% 

Iron and aluminium oxides . 0.91- 1 . 90% 

^lagnesium carbonate . 96% 

Silica 0.60- 0.73% 

Moisture and loss 0.40- 1.17% 

The rock asphalt is also removed in large blocks which are capable of being 
sawed, bored, or carved in the form of paving stones, stair treads, or ornamental 
work for buildings. The dark color of the asphalt as freshly mined soon disappears 
upon exposure to the w^eather, turning to a bluish gray. 

Greece 
District of Triphily 

At Marathonpolis on the west coast of Peloponnes, there occurs a deposit of 
asphaltic hmestone well suited for the preparation of asphalt mastic pavements, 
analyzing as follows: 



124 ASPHALTS AND ALLIED SUBSTANCES 

Asphalt 14 . 75% 

Silica 1 . 07% 

Iron and aluminium oxides . 80% 

Calcium sulphate 0.21% 

Magnesium carbonate . 45% 

Calcium carbonate 82 . 27% 

Moisture and loss . 45% 



Total 100.00% 

The asphalt is reported to have a comparatively high fusing-point. 

Portugal 

Province of Estremadura. At Serra de Cabagoa deposits of asphaltic sandstone 
have been reported, and at Monte Real, north of Leira, layers of asphaltic sand- 
stone impregnated with a very soft and viscous asphalt exist. None of these have been 
worked to any great extent. 

Spain 

Province of Santander. In the neighborhood of Puerto del Escudo, deposits 
of asphaltic sandstone are found in beds about 5 ft. thick. No analyses are avail- 
able. At Suances similar deposits of asphaltic sandstone have been reported con- 
taining approximately 11 per cent of asphalt. 

Province of Alava. At Alauri and other localities in the Pyrenees, asphaltic 
sandstone deposits containing 12 to 20 per cent of asphalt have been worked 
for a number of years. A mine about 10 miles from Vittoria consists of a cal- 
careous sandstone impregnated with 8 to 9 per cent of asphalt. It shows the 
following average composition: 

Asphalt 8.80% 

Silica 68.75% 

Iron and aluminium oxides 4 . 35% 

Calcium and magnesium carbonates 17 . 25% 

Water and loss 0.40% 

Province of Navarre. Similar deposits have been reported at Bocaicoa, which 
have been worked to a limited extent. 

Province of Tarragona. In the Santa Catalina mountains outcrops of asphaltic 
shale are reported. No data concerning these are available. 

Province of Soria. At Santander and Sierra de Frentes several deposits of 
asphaltic sandstone have been operated, from which fairly large quantities have 
been mined. 

Russia 
Province of Terek 

At Vladikavkaz near the city of Gudermes an asphalt deposit has been known 
to exist for some time, containing betweer 6 and 12 per cent of a very soft asphalt 
associated with earthy matter. 

At Michaelovskaja in the Caucasus Mountains, a rich deposit is found, con- 
taining 86 i per cent of asphalt and the balance mineral matter. The extracted 
asphalt melts at about 300° C, and is extremely hard and brittle, having a specific 
gravity of about 1.2. The portion soluble in carbon disulphide contains: carbon 



NATIVE ASPHALTS ASSOCIATED WITH MINERAL MATTER 125 

75.42 per cent, hydrogen 7.86 per cent, nitrogen 0.06 per cent, sulphur 0.8 per cent, 
and ash 4.35 per cent.^ 

Near Sernowodsk in this same region, a similar deposit of asphalt is found 
associated with clay, which analyzes similarly to the preceding. 

Province of Simbirsk 

Extensive deposits of asphalt are found at Syzran, along the banks of the 
Syzranka River, extending to the Samarskaya-Luka Mountains. The product ag 
mined has the following composition: 

Asphalt 30.50% 

Calcium carbonate. 66.23% 

Magnesium carbonate 3 . 27% 

Total 100.00% 

In this same region near the River Volga there is an occurrence of liquid asphalt 
containing about 20 per cent asphalt associated with sand, covering an area 1300 
by 320 ft. in a layer about 32 ft. deep. 

ASIA 
Japan 

Ugo Province. An asphalt deposit has been reported in this locality, but no 
exact data are available. ^ 

Asiatic Russia 

Province of Uralsk. At the mouth of the Ural River, where it empties into 
the Caspian Sea, deposits of asphalt have been found, but no complete data or 
analyses are reported. 

Syria 

At Mrani, deposits of asphaltic Hmestone have been reported containing between 
10 and 30 per cent of asphalt. 

A large deposit is located at Bir-el-Hummar a short distance from Hasbaya 
(see p 135) composed of limestone impregnated with an average of 10 per cent 
of asphalt. Petrified fish remains are also present, indicating that it is of animal 
origin. It is said to have a comparatively high fusing-point. Similar deposits 
have been reported at Khaliwet, between Hasbaya and Rascheya, also at Ain- 
Ettineh, 70 miles east of Beirut.^ 

Deposits of asphaltic limestone are reported on the eastern shore of the Dead 
Sea between Kerak and Ouadi Kerak, also on the western shore near Masada and 
Ouadi Sebbi. A short distance from this locality, on the Ouadi River, peculiar 
formations occur, composed of flint pebbles cemented together with varying per- 
centages of asphalt. This asphaltic conglomerate lies in juxtaposition to a vein 
of asphaltic limestone. 

i"New Deposits of Asphaltum," K. Charitschkow, Chem.-Zeit., 31, Rep. 116, 1907. 

2 Rychei Katayama, Beitrdge zur Mineralogie von Japan, 5, 303, 1915; Chem. Abs., 10, 1831, 1916. 

3 "Asphalt Mines in Syria," Reports from the Consuls of the U. S., 42, [153], 228, 1893. 



126. ASPHALTS AND ALLIED SUBSTANCES 

Asphalt] c limestone is also found at Nebi Mousa, on the northwest shore of 
the Dead Sea, containing 25 per cent of asphalt, also a quantity of fossil marine 
remains. It is used by the natives as a fuel and for paving purposes. Similar 
deposits have been reported at Tiberias, Hamman and Jarmuktale. 

Mesopotamia 

- At Hit on the Euphrates River, asphaltic limestone is still found, and collected 
in a crude way by the natives, exactly as was the case many centuries before. 
(See page 5.) 

Arabia 

In 1902 an extensive deposit was discovered on the Island of Bahrein, in the 
Persian Gulf, which on analysis was found to consist of: 

Asphalt 22.77% 

Ash 76.68% 

Moisture 0. 59% 

Total 100.04% 

The ash consists almost exclusively of calcium-aluminium-silicate. The product 
is mixed with limestone powder and used for paving purposes. 



AFRICA 
Algeria 

Province of Oran. At Constantine, asphaltic limestone is found in veins 32 ft. 
thick, containing as much as 40 per cent of asphalt. In many places the rock 
is so saturated that the asphalt seeps out and forms pools having a fusing-point 
of about 140° F. (K. and S. method), a penetration of 11 at 77° F., and con- 
taining 0.9 per cent of sulphur. The limestone is largely crystalline. 

Nigeria 

Bituminous sands are reported in southern Nigeria a short distance from the 
coast. Attempts have been made to purify the asphalt by the water-extraction 
process, but so far this has resulted in failure. The extracted material contains 
about 70 per cent of asphalt, 10 per cent of organic substances other than asphalt 
and 20 per cent of sand. 

Ehodesia 

Rock asphalt has recently been reported in northern Rhodesia, but is not yet 
thoroughly investigated. 



CHAPTER X 
ASPHALTITES 

AsPHALTiTES are natural asphalt-like substances, characterized by 
their high fusing-points (over 250° F.). They are grouped into three 
classes, namely: gilsonite, glance pitch, and grahamite. Since all are 
presumably derived from the metamorphosis of petroleum, one would 
naturally expect the classes to merge into one another, and such actually 
proves to be the case. 

The author has adopted the following means of differentiating the 
three classes, one from another: 



Gilsonite or Uintaite 

Glance Pitch or Manjak *. 
Grahamite* 



Streak. 



Brown 

Black 

Black 



Specific Gravity 
at 77° F. 



1.05-1.10 
1.10-1.15 
1.15-1.20 



Fusibility, 

(K.&S. Method) 

Deg. F. 



250-350 
250-350 
350-600 



Fixed Carbon 
Per Cent. 



10-20 
20-30 
30-55 



When substantially free from mineral matter. 



In all three classes the non-mineral constituents are almost completely 
soluble in carbon disulphide. The physical and chemical characteristics 
will be described in greater detail under the respective headings. 



GILSONITE OR UINTAITE 

This asphaltite is found in but one region,^ extending from the 
eastern portion of the State of Utah across the boundary line into 
the western portion of Colorado. It occurs in a number of parallel 
vertical veins, varying in width from thin fissures to several feet. 

1 "Gilsonite or Uintaite," J. M. Locke, Trans. Am. Inst. Mining Eng., 16, 162, 1887; 
" Notes on a Specimen, of Gilsonite from Uinta County, Utah," R. W. Raymond, Trans. 
Am. Inst. Mining Eng., 17, 113, 1888; "Nature of Uintaite," Dr. Henry Wurtz, Eng. and Mining 
J., 48, 114, 1889; "The Uintaite (Gilsonite) Deposits of Utah," by G. H. Eldridge, 17th Annual 
Report U. S. Geol. Survey, Wash., D. C, p. 915, 1896; W. T. Day, J. Franklin In.'^t.. 1(0, 
221, 1896; 22d Annual Report of the U. S. Geol Survey, Wash., D. C, G. H. Eldridge, part I, 
pp. 327 and 340, 1901; "The Production of Asphalt, Related Bitumens and Bituminous Rock 
in 1910," by D. T. Day, U. S. Geol. Survey, Wash., D. C, p. 6, 1911; "Modern Asphr.H, 
Pavement," p. 208, 1908; "The Hydrocarbons of Utah," by Bardwell, et al., /. Ind. Eng. Chcm. 
5, 973, 1913; 6, 865, 1914; "Gilsonite and Grahamite," by Clifford Richardson, J. Ind. Eng. 
Chem., 8, 496, 1916. 

127 



128 ASPHALTS AND ALLIED SUBSTANCES 

In all the veins the gilsonite is fairly uniform in composition and 
complies with the following characteristics: 

(Test 1) Color masa Black 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Bright to fairly bright 

(Test 6) Streak Brown 

(Test 7) Specific gravity at 77° F 1.05-1.10 

(Test 9a) Hardness on Moh's scale 2 

(Test 96) Hardness, needle penetrometer at 77° F 

(Test 9c) Hardness, consistometer at 115° F 40-60 

Hardness, consistometer at 77° F 90-120 

Hardness, consistometer at 32° F Too hard for test 

(Test 9d) Susceptibility factor > 100 

(Test 10a) Ductility at 77° F. (Author's Method) 

(Test 13) Odor on heating Characteristie 

(Test 14a) Behavior on melting Forms a compar- 
atively thick, 
viscous melt. 

(Test 146) Behavior on heating in flame Softens and flows 

(Test 15o) Fusing-point (K. and S. method) 250-350° F. 

(Test 156) Fusing-point (Ball and Ring method) 270-370° F. 

(Test 16) Volatile at 325° F., 7 hrs. (dry substance) Less than 2% 

Volatile at 400° F., 7 hrs Less than 4% 

Volatile at 500° F., 4 hrs Less than 5% 

(Test 19) Fixed carbon 10-20% 

(Test 20) Distillation test: 

0-150° C 9.34% distillate 

150-200° C 5.35% distillate 

200-250° C 12.84% distillate 

250-300° C 28.99% distillate 

Above 300° C Coked 

(Test 21a) Soluble in carbon disulphide Greater than 98% 

(Test 216) Non-mineral matter insoluble 0-1% 

(Test 21c) Mineral matter Tr.-1% 

(Test 22) Carbenes 0-^% 

(Test 23) Soluble in 88° naphtha 40-60% 

(Test 24) Grams soluble in 100 grams of cold solvent: 

Amyl acetate 86 

Amyl alcohol Insoluble 

Amyl nitrate 51 

Aniline .■ Insoluble 

Benzol 71 

Carbon disulphide Soluble in all pro- 
portions 

Carbon tetrachloride 44 

Chloroform 54 

Ethyl acetate 3 

Ethyl alcohol Insoluble 

Ethyl ether Soluble in all pro- 
portions 

Naphtha 62° 5 

Nitrobenzene 9 

Propyl alcohol Insoluble 

Toluol 72 

Turpentine 60 

(Test 26) Carbon 88 -89.5 

(Test 27) Hydrogen 8.5-10.0 

(Test 28) Sulphur 1.7- 2.0 

(Test 29) Nitrogen 0.8% 

(Test 30) Oxygen 0-2% " 



ASPHALTITES 



129 



(Tegt 33) Paraffine scale O-Tt.% 

(Test 35) Sulphonation residue 85-95% 

(Test 37) Saponifiable matter Tr. 

(Test 41) Diazo leaction No. 

(Test 42) Anthraquinone reaction No. 

Gilsonite is assorted and marketed in two varieties, known as '* selects " 
or '* firsts," and " seconds " respectively. The *' firsts " are taken 
from the centre of the vein and are characterized by a conchoidal and 
lustrous fracture. The " seconds " occur near the vein walls and are 
characterized by a semi-conchoidal and semi-lustrous fracture. In 
other respects, however, they are alike. 

Fig. 45 shows the hardness, tensile strength (muItipHed by 10) and ductihty 
curves of a mixture of gilsonite and residual oil fluxed together so as to have 



100 






IV 








770 






115 













\ 




91.0 










1 




- Hardness 


90 




/ 


^^ 


\ 




•H : 


^^ 








/ensue OTrengrn X i{,>\ 


SO 
■70 

eo 

50 
40 
10 
20 
10 




^'i:.'"."/ .,^Or- 






\ 


(68. 






\ 

\ 






@ Fusing Hoim= i^l r. 
Susceptibility Factor = 45. 7 








& 




\ 


\ 


























\ 


\, 






^ 


55.0 


























S 


\, 






\ 




























s 


\ 




\ 




• 


_ 


\'^ 


10 






















N 


f^^ 


\ 


/ 

/ 




\i 


\ 
























N 


>i 


^N 




-7' 


\ 


N. 




















I.O 


• 


' 




7^ 


==^ 


'*'v 







10 20 30 40 50 60 70 60 90 100 110 120 150 UO 150 160 
Temperature, Degrees Fahrenheit 

Fig. 45. — Chart of Physical Characteristics of Fluxed Gilsonite Mixture. 



a hardness of exactly 25.0 at 77° F. The resulting mixture contained gilsonite, 
47 per cent and residual oil, 53 per cent. The fusing-point of the gilsonite used 
was 285° F. (K. and S. method), and that of the resulting mixture 142° F. 

Gilsonite is one of the most valuable asphalts for manufacturing paints and 
varnishes (see p. 471). Gilsonite and glance pitch mix readily in all proportions 
with fatty-acid pitches, thus differing from grahamite. Products involving the use 
of gilsonite formed the basis of several patents granted to Gilson, after whom the 
material was named.* 

» U. S. Patents 361,759 of Apr. 26, 1887; 362,076 of May 3. 1887; 415,864 of Nov. 26, 1889 
to S. H. GUson. 



130 ASPHALTS AND ALLIED SUBSTANCES 

UNITED STATES 
Utah. 

Uinta County. Practically all gilsonite is mined in the ''Uinta 
Basin/' at the junction of the Green and White Rivers south of Fort 
Duchesne, Utah, from a point 4 to 5 miles within the Colorado bound- 
ary line (Rio Blanco county), extending westward about 60 miles into 
Utah. A large number of veins have been located in this area, and 
extending from a northwesterly to a southeasterly direction, and all of 
them parallel or nearly so. The veins vary in width from a fraction 
of an inch to 18 ft., and some of the longest, such as the Cowboy or 
Bonanza, have been traced 8 miles. The veins are almost vertical with 
fairly smooth and regular rock walls, and although they are usually 
continuous, they may in certain cases be interrupted in the direction 
of the fissure. Very frequently branch veins join the main one, form- 
ing very acute angles. 

Near the outcrop where it has been exposed to the weather, gilsonite 
loses its brilliant lustre, changing to a dull black. Along the vein walls 
it shows a columnar structure, extending at right angles to the wall, which 
is characteristic of all asphaltites. The rock walls are often impregnated 
with gilsonite J to 2 ft., so there is no visible line of demarcation between 
the impregnated and non-impregnated portions. In shale formation the 
impregnated zone is smaller than when the gilsonite is found in a porous 
sandstone. 

The following are the principal veins occurring in this region: 

Duchesne Vein. This occurs about 3 miles east of Fort Duchesne, 

fiUing a vertical crack in sandstone and shale. The 

vein has been traced for 3 miles, and is 3 to 4 ft. 

wide for about IJ miles, tapering at the ends, until 

it completely disappears. A comparatively large 

quantity of gilsonite has been mined from. this vein. 

Culmer Vein. This is also known as the 

" Pariette Mine," and occurs in the '' Castle Peak '* 

mining district. It has been traced 7 miles and 

varies in width from a fraction of an inch to 30 ins., 

averaging about a foot. Several branch veins are 

connected with the main one at very acute angles. 

It also shows a number of transverse faults as 

^ ' ^ T^. ^., illustrated in Fig. 46, in which the lateral displace- 

FlG. 46.— Faults in Gil- r i + m f+ rpu ' a. a ^ 

soniteVein. ments vary from 1 to 10 ft. The associated rock 

consists of sandstone and shale. 

Bonanza and Cowboy Veins. These are shown in Fig. 47 and embrace 




ASPHALTITES 



131 



oovaoTOO 
HVin . : 



_aNn 

AMVONnOQ 




o 

P4 



o 

o 

i- 
s 

I 



132 



ASPHALTS AND ALLIED SUBSTANCES 



three veins known as the Cowboy Vein, the East Branch and the West 
branch respectively of the Bonanza Vein. The last two are joined together 
near the southern end. These veins occur in sandstone and shale. The 




Courtey of American Asphalt Association. 
Fig. 48. — View of Cowboy Gilsonite Mine, Utah. 

shale being harder than the sandstone, seems to have offered greater 
resistance to the intrusion of gilsonite, and the veins are not therefore 
as wide when they occur in the latter. The disappearance of the veins 
to the northwest also occurs in shales, and as the gilsonite passes from 



ASPHALTITES 133 

sandstone into shale, it splits up into a number of smaller veinlets, which 
gradually thin into fine hair-like fissures. 

The Cowboy is the largest and attains a maximum width of 18 ft., 
maintaining a width of 8 to 12 ft. for 4 miles. Its total length is 7 
to 8 miles. A typical view of the Cowboy Mine is shown in Fig. 48. 

The Bonanza Veins have been followed for 7 miles, but they are not as 
wide as the Cowboy. 

A number of smaller veins also occur in this region, including the 
" Rainbow," " Harrison," *' Colorado," etc., which are narrower and 
shorter than the foregoing. 

Black Dragon Vein. This occurs southwest of Evacuation Creek, a 
tributary of the White River, near the Colorado Hne. It has been traced 
for 4 miles, and averages between 2 and 3 ft. wide, the maximum being 8 
ft. near the southern end. It is associated with sandstone, hmestone 
and shale. In some places, the rock is impregnated with gilsonite 1 to 3 
ft. along side of the vein proper. A branch railroad runs from Dragon, 
Utah, connecting with the Denver & Rio Grande R. R. at Mack, Colo- 
rado, from which point most of the gilsonite is shipped East. 

The methods of mining the gilsonite are very crude, and involve the 
use of a pick and shovel, together with some sort of simple hoisting 
apparatus. Very little if any timber is required, as the veins are nearly 
vertical, and the surrounding rock is firm and self-supporting. The 
gilsonite is shipped in sacks holding about 200 lbs. One man can mine 
and sack an average of 2 tons per day 10 of hours. Approximately 
20,000 tons of gilsonite are mined and shipped from this region each 
year. It is estimated that 32,000,000 tons of gilsonite are still available 
in the entire region. 

GLANCE PITCH 

Glance pitch resembles gilsonite in the external appearance, with 
the exception of the streak, which is a decided brown in the case of gil- 
sonite, and black in the case of glance pitch. It also differs in having a 
higher specific gravity and producing a larger percentage of fixed carbon. 
It always has a brilUant conchoidal fracture, and a fusing-point between 
250 and 350 ° F. (K. and S. method). In general, glance pitch complies 
with the following characteristics: 

(Test 1) Color in mass Black 

(Test 4) Fracture Conchoidal to hackly 

(Test 5) Lustre Bright to fairly bright 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity at 77° F 1 . 10-1 . 15 

(Teat 9o) Hardness, Moh's scale 2 



134 ASPHALTS AND ALLIED SUBSTANCES 

(Test 96) Hardness, needle penetrometer at 77° F 

(Test 9c) Hardness, consistometer at 77° F 90-120 

(Test 9d) Susceptibility factor > 100 

(Test 10) Ductility at 77° F 

(Test 13) Odor on heating Asphaltie 

(Test 14a) Behavior on melting Forms a comparatively 

thick and viscous melt 

(Test 146) Behavior on heating in flame Softens and flows 

(Test 15a) Fusing-point (K. and S. method) 250-350° F. 

(Test 156) Fusing-point (Ball and Ring method) 270-375° F, 

(Test 16) Volatile at 325° F., 7 hrs. (dry substance) Less than 2% 

Volatile at 400° F., 7 hrs Less than 4% 

(Test 19) Fixed carbon 20-30% 

(Test 21a) Soluble in carbon disulphide Usually greater than 95% 

(Test 216) Non-mineral matter insoluble Less than 1% 

(Test 21c) Mineral matter Less than 5% 

(Test 22) Carbenes . Less than 1 . 0% 

(Test 23) Soluble in 88° naphtha 20-50% 

(Test 26) Carbon 80-85% 

(Test 27) Hydrogen 7-12% 

(Test 28) Sulphur 2-8% 

(Test 29) Nitrogen and oxygen A trace to 2% 

(Test 33) Paraffine O-Tr.% 

(Test 35) Sulphonation residue 80-95% 

(Test 37) Saponifiable matter Tr. . 

(Test 41) Diazo reaction No. 

(Test 42) Anthraquinone reaction No. 

Glance pitch appears to be intermediate between the native asphalts 
and grahamite. It is probably derived from a different character of 
petroleum than gilsonite, having nevertheless reached a parallel stage 
in its metamorphosis, under approximately the same external conditions. 

Mexico 

Chapapote. As stated previously (p. 86), deposits of very pure asphalt occur 
in this locality, varying from very soft consistency to a hard and brittle asphaltite, 
properly classified as "glance pitch." They show a lustrous and conchoidal frac- 
ture, a black streak, fuse in the neighborhood of 250° F. (K. and S. method), 
contain over 20 per cent of fixed carbon, and are more than 99 per cent soluble 
in carbon disulphide. 

West Indies 

Barbados. Glance pitch was first reported in 1750 by Griffith Hughes, and 
since 1896 has been mined almost continuously. Deposits occur in a number of 
localities throughout the island, especially in the Conset district, at Groves, Spring- 
field, St. Margaret, Quinty, and Burnt Hill. This asphaltite has been marketed 
under the name of ''manjak," which was originally applied to the Barbados prod- 
uct, although the name was subsequently associated with a variety of grahamite 
mined in Trinidad- (see p. 146). The deposits were first worked on a commercial 
scale by Walter Merivale in 1896, who also accurately described the deposit, and 
the properties of the mineral. 

Barbados manjak contains a very small percentage of sulphur (between 0.7 
and 0.9 per cent), and about 1-2 per cent of mineral matter. Its specific gravity 



ASPHALTITES 135 

at 77** F. is in the neighborhood of 1.10, fusing-point 320-340° F. (K. and S. 
method), the percentage of fixed carbon as reported by different observers varies 
between 25 and 30 per cent and its solubility in carbon disulphide 97-98 per cent. 
Near the surface, the manjak is hard and brittle with a high fusing-point, but 
at the lower levels of the mines it is found softer, and with a much lower fusing- 
point, partaking of the nature of an asphalt, rather than an asphaltite, and clearly 
proving the metamorphosis of one from the other. It also indicates that the 
manjak originated in the lower strata, having been thrust upward in the form of 
a dyke (see also Trinidad grahamite, p. 146). 

It is used largely for the manufacture of varnishes and japans on account of 
its high purity, gloss, and intense black color. ^ 

Santo Domingo (Hayti). A deposit of glance pitch similar to the preceding 
has been reported near Azua on the Bay of Ocoa. This has not been developed 
commercially, nor are analyses available. 

Colombia, South America 

Very large deposits of glance pitch occur at Chaparral, in the Province of Tolima, 
on the Saldana River, which empties into the Magdalena River. The deposit is about 
100 miles southwest of Bogota. It is transported by boats down the Magdalena River 
to the coast, whence it is exported. About 2000 tons are shipped annually, having a 
high-fusing point, and over 99 per cent soluble in carbon disulphide. ^ It is used largely 
for the manufacture of varnish, and tests as follows: 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Bright 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1.12 

(Test 8a) Hardness, Moh's scale 2 

(Test 8b"; Hardness, penetrometer . , , , . 

(Test 146) Heating in flame Softens and burns 

(Test 15) Fusing-point (K. and S. method) 275° F. 

(Test 19) Fixed carbon 26 . 45% 

(Test 2Ia) Solubility in carbon disulphide 96.0% 

(Test 216) Non-mineral matter insoluble 0.7% 

(Tesc 21c) Mmeral matter 3.3% 

Syria 

Hasbaya. This constitutes one of the most important asphaltite deposits in the 
region. It is located about 40 miles southeast of Beirut, and west of Mt. Hamon. 
It has a bright, black lustre, and a black streak. It contains from a trace to about 
5 per cent mineral matter, and fuses at 275° F. It shows 27.0 per cent fixed 
carbon, and on analysis: carbon, 77.18 per cent; hydrogen, 9.07 per cent; sulphur, 
0.40 per cent; nitrogen, 2.10 per cent; and mineral matter, 0.50 per cent. The 
deposit has been worked extensively, and a number of years ago fairly large quan- 
tities were exported to the United States for the manufacture of varnishes. 

Dead Sea. This deposit is merely of historical interest, as it constituted one 
of the most important sources of supply for the ancients (p. 5). There appear 

J Merivale, Trans. Fed. Inst. Eng., 14, 539, 1896; also 16, 33, 1898; Bedson, Trans. Am. Inst. 
Mining Eng., 16, 388, 1899; Emtage, J. Royal Soc. Arts, 62, 367, 1904; Garrett, J. Soc. Chem. 
Ind., 31. 314, 1912. 

2/. Soc. Chem. Ind., 23, 278, 1904. 



136 ASPHALTS AND ALLIED SUBSTANCES 

to be large veins of asphalt at the bottom of the Dead Sea, the water of which 
is saturated with salt (25 per cent in solution) having a gravity of about 1.2L 
The asphalt has a specific gravity at 77° F. of 1.104, and as masses become de- 
tached at the bottom by earthquake shocks or otherwise, they float to the surface, 
'where they are gathered up by natives. A section through the Dead Sea showing 
the veins of asphalt is illustrated in Fig. 49. This glance pitch shows a lustrous 




(Asphalt Vein 
Fig. 49. — ^Vertical Section through Dead Sea Showing Glance Pitch Veins. 

conchoidal fracture, and a black streak. Its fusing-point is 275° F., over 99 per 
cent is soluble in carbon disulphide, and it yields 20 per cent of fixed carbon. 
The supply is limited and the material is used only to a small extent locally.* 

Egypt 

A deposit of Glance Pitch has been reported in the Arabian Desert between 
the Nile and the Red Sea in the neighborhood of Neapolis. It has a specific 
gravity of 1.10 at 77° F., a conchoidal lustrous fracture, a black streak, fuses at 
265° F., and contains over 99 per cent soluble in carbon disulphide. 

GRAHAMITE 

This asphaltite varies considerably in composition and physical prop- 
erties, some deposits occurring fairly pure and others are associated 
with considerable mineral matter, running as high as 50 per cent.^ In 
general, however, it complies with the following: 

(Test 1) Color in mass Black 

(Test 4) Fracture Conchoidal to hackly 

(Test 5) Lustre Very bright to dull 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity at 77° F.: 

Pure varieties (containing less than 10% mineral 

matter) 1.15 -1 . 20 

Impure varieties (containing more than 10% 

mineral matter) . 1 . 175-1 . 50 

» /. Roy. Soc. Arts, 66, 829, 1908. 

2 "Grahamite, A Solid Native Bitumen,' by Clifford Richardson, J. Chem. Soc, 32, 1032,1910; 
"Gilsonite and Grahamite; the Result of the Metamorphism of Petroleum under a Particular Environ- 
ment," by Clifford Richardson, J. Ind. Eng. Chem., 8, 493, 1916. 



ASPHALTITES 137 

(Test 9a) Hardness, Moh's scale 2-3 

(Test 96) Hardness, needle penetrometer at 77° F 

(Test 9c) Hardness, consistometer at 77° F Over 150 

(Test 9d) Susceptibility factor > 100 

(Test 146) Behavior on heating in flame: 

"Variety showing a conchoidal fracture and a 

black lustre Decrepitates violently 

Variety showing a hackly fracture and a fairly 

bright to dull lustre Softens, splits and burns 

(Test 15a) Fusing-point (,K. and S. method) 350-600° F. 

(Test 156) Fusing-point (Ball and Ring method) 370-625° F. 

(Test 16) Volatile at 500° F., 4 hrs Less than 1% 

(Test 19) Fixed carbon 30-55% 

(Test 21o) Soluble in carbon disulphide 45-100% 

(Test 216) Non-mineral matter insoluble in carbon disulphide. . Lf.ss than 5% 

(Test 21c) Mineral matter Variable (up to 50%) 

(Test 22) Carbenes 0-80% 

(Test 23) Soluble in 88° petroleum naphtha Tr.-50% 

(Test 30) Oxygen in non-mineral matter 0-2% 

(Test 33) ParafEne O-Tr.% 

(Test 35) Sulphonation residue 80-95% 

(Test 37) Saponifiable matter Tr. 

(Test 41) Diazo reaction , No. 

(Test 42) Anthraquinone reaction No, 

In general, grahamite is characterized by the following features: 

(1) High specific gravity; 

(2) Black streak; 

(3) High fusing-point; 

(4) High percentage of fixed carbon; 

(5) Solubility of non-mineral matter in carbon disulphide. 

The individual deposits cf grahamite occur in the following localities: 

United States 

West Virginia 

Ritchie County. The original deposit of grahamite was discovered in West 
Virginia. 1 It was first described by Prof. J. P. Leslie in a paper read before the 
American Philosophical Society, March 20, 1863. It is found in but a single 
locahty in Ritchie County, about 25 miles southeast of Parkersburg. The grahamite 
fills an almost vertical fissure in sandstone, a mile long, varying in width from 
2 ins. at the ends to 4 and 5 ft. in the centre. Its depth is assumed to be 150C 
to 1600 ft. 

The mine has been long abandoned, as the available supply of grahamite is 
exhausted. Fig. 50 shows a view of the opening in the hillside from which the 
grahamite has been removed. Fig. 51 shows the nature and extent of the the 
workings. Next to the sandstone walls, the grahamite shows a coarsely granular 
structure, with a semi-dull fracture. The following layer is highly columnar in 
structure with a lustrous fracture. Finally in the centre of the vein, the grahamite 

ij. P. Leslie, Proe. Am. Phil. Soc, 2, 1863; Prof. Henry Wurtz, Proe. Amer. Soc. for the Adv. 
of Science, 18, 124, 1869; " Uintaite, Albertite, Grahamite, and Asphaltum Described and Compared, 
with Observations on Bitumen and its Compounds," by W. P. Blake, Trans. Am. Inst. Mining Eng., 
18, 563-82, 1889; W. M. Fontaine, Am. J. Sci., 8, October 14, 1873, Second Series; I. C. White, 
Bull. Geological Soc. Am., 10, 277, 1899. 



138 



ASPHALTS AND ALLIED SUBSTANCES 



is more compact and massive, with the columnar structure less developed and a 
semi-dull fracture. This variation in structure, fracture and lustre is characteristic 
of grahamite deposits. 




Fig. 50. — View of Grahamite Vein, Ritchie County, West Virginia. 



On analysis it tests as follows: 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity at 77° F 1 . 18-1 . 185 

(Test 9a) Hardness on Moh's scale 2 

(Test 146) Behavior on heating in flame Softens, burns and splits 

(Test 15o) Fusing-point (K. and S. method) 520-540° F. 

(Test 19) Fixed carbon 42. 15 and 42.48% 

(Test 21o) Soluble in carbon disulphide: 

Non-mineral matter 97.61% 

Combined mineral matter 0.44% 

(Test 216) Non-mineral matter insoluble 0.17% 

(Test 21c) Free mineral matter 1 . 71% 

Total 99.93% 



ASPHALTITES 



139 



(Test 22) Insoluble in carbon tetrachloride 55.0% 

(Test 23) Soluble in 88° naphtha 3.0% 

(Test 25) Hydroscopic moisture . 07% 

(Test 26) Carbon 86 . 56% 

(Test 27) Hydrogen 8.68% 

(Test 28) Sulphur 1 . 79% 

Difference 2 . 97% 




',y/vy/>y/y/V/y/WVy///7^//V///^^^^^ 



Elevation 



Fossib/y Mined Out 
below here 



8'Wide 



"Wide 



,^ Fissure above Fauft 
i 24'Wide 30'Wide 



36'Wide 



6'Wide 



\ 50"Wide 

'Fissure below Fault 



56'Wick 
Plan 



4Z'y/ide 



Fig. 51. — Sections through Grahamite Mine, Ritchie County, W. Va. 



Texas 



Fayette and Webb Counties. Richardson ^ reports a deposit of grahamite in 
Fayette County in the neighborhood of Lagrange, also an occurrence in Webb 
County, near Laredo, in the southern portion of the State. These test as follows: 





Fayette County 
Grahamite. 
Per Cent. 


Webb County 
Grahamite. 
Per Cent. 


(Test 19) 


Fixed carbon 


37.7 
4.2 
0.3 

76.2 
6.6 
7.4 
0.4 
5.2 


52.8 


(Test 21c) 


Mineral matter 


2.9 


(Tesc 25) 




0.3 


(Test 26) 
(Test 27) 
(Test 28) 
(Test 29) 


Carbon 

Hydrogen 

Sulphur 

Nitrogen . . 


78.6 
7.5 
5.4 
1.2 




Undetermined 


5.1 



J. Am. Chem. Soc. 32, 1032, 1910. 



140 



ASPHALTS AND ALLIED SUBSTANCES 



Oklahoma ^ 

Pushmataha County. Two small occurrences are reported in the Potato Hills 
about 5 miles north of Tuskahoma. One is in SE i, Sec. 1, T 2 N, R 19 E, 
and the other in NE I, Sec. 2, T 2 N, R 19 E. Neither of these is of importance. 

Jackfork Creek Deposit. The largest known grahamite vein in the 
world occurs in Jackfork Valley, 12 miles west of Tuskahorna in the 
SE i, NE i, Sec 9, T 2 N, R 18 E. It is about 1 mile long, and varies 
in thickness from 19 to a maximum of 25 feet. At the surface the vein 
dips an an angle of 37°, and after continuing downward for 140 feet, 
turns suddenly to an angle between 45 and 50°. It is illustrated in 
Fig. 52. The grahamite fills a fault in shaly sandstone. The upper wall 




Courtesy of Central Commercial Co. 

Fig. 52. — ^Vertical Section through Grahamite Mine Near Tuskahoma, Okla. 

of the vein is firm and requires no timbering. In mining the material, 
cave-ins are prevented by allowing pillars of grahamite to remain in place 
to support the upper " hanging'' rock wall. When the author visited the 
mine in 1912, a track was laid along the bottom wall, and the grahamite 
hoisted out in skips on a cable- way. There is evidence of large pieces 
of rock having become detached from the hanging wall and fallen into the 
deposit of grahamite before it became solid. 

As is common with most grahamite deposits, several distinct types 
of material are found in the vein. The grahamite which occurs along the 
rock walls for a thickness of 2 to 6 ft. shows a hackly (known as a '' pencil- 

. - '"Grahamite Deposits of Southeastern Oklahoma," by J. A. Taff, Contributions to Economic 
Geology; Bull. 380, U. S. Geol. Survey, p. 286, 1908; "Asphalt and Petroleum in Oklahoma," by 
L. L. Hutchison, Bull. 2, Okla. Geol. Survey^ Guthiie, 1911. 



ASPHALTITES 



141 



lated ") fracture, and a semi-dull to dull lustre, whereas the grahamite 
taken from the centre of the vein shows a conchoidal fracture and very 
bright lustre similar to gilsonite. This is probably due to the fact that 
the grahamite in contact with the wall cooled more rapidly than the central 
portion, and very likely has also been subjected to more or less strain 
from movements of the surrounding rock. Many thousand tons of gra- 
hamite have been mined from this vein which is now pretty nearly 
exhausted (from 6000 to 7000 carloads during the first four years, of its 
operation, and at the time of the author's visit about 50 tons per day) 
The cost of a moving to the surface is comparatively small (80c. to $1.00 
per ton), but the material has to be carted 10 miles to Tuskahoma, the 
nearest shipping point (costing about $2.50 per ton). 

On analysis it tests as follows: 

(Test 1) Color in mass Black 

(Test 4) Fracture (a) Conchoidal 

Fracture (6) Hackly 

(Test 5) Lustre (a) Bright 

Lustre (6) Semi-bright to dull 

(Test 6) Streak (a and b) Black 

(Test 7) Specific gravity at 77° F. (o and 6) 1.18-1.195 

(Test 9a) Hardness, Moh's scale 2 

(Test 146) Behavior on heating in flame (a) Intumesces violently 

Behavior on heating in flame (b) Softens, splits and burns 

(Test 15a) Fusing-point (K. and S. method) (a and b) 530-604° F. 

Note. There is no appreciable difference in fusing-point between the two varieties (o and b). 

(Test 16) Volatile matter 500°, 4 hrs Less than 1% 

(Test 19) Fixed carbon (a and b) 52 . 76-55 . 00% 

(Test 21a) Solubility in carbon disulphide Greater than 99.5% 

(Test 216) Non-mineral matter insoluble Less than 0.5% 

(Test 21c) Free mineral matter (a and 6) 0.21-0.70% 



100 

90 
60 
70 

eo 

50 
40 
50 
10 
10 
0, 



ZZ' 



ir 



115^ 




Hardness 



Tensile Strength x 10 

^^ Ductility 

® Fusing Point =277 '^F 
Susceptibility Factor =12.4 



10 10 30 40 50 60 70 50 90 100 110 120 130 140 150 160 
Temperature, Degrees Fahrenheit 



Fig. 53. — Chart of Physical Characteristics of Fluxed Oklahoma Grahamite Mixture. 



142 ASPHALTS AND ALLIED SUBSTANCES 

Fig. 53 shows the hardness, tensile strength (multiplied by 10) and ductility 
curves of a mixture of the grahamite and residual oil, fluxed together so as to 
have a hardness of exactly 25.0 at 77° F. The mixture contains: grahamite, 60 
per cent; and residual oil, 40 per cent. The resulting fusing-point (K. and S. 
method) was 277° F. The same residual oil was used in this test as for the 
gilsonite in Fig. 54, and the fusing-point of the grahamite used was 550° F. 
(K. and S. method. ).i 

Impson Valley Deposit. This occurs on a branch of the Tenmile Creek on 
the SW I Sec. 21 and NW h Sec. 28, T 1 S., R 14 E., about 16 miles northwest 
of Antlers. It is known under various names such as Jumbo Mine, Choctaw Mine, 
or Old Slope Mine. This is the second largest deposit in the State of Oklahoma. 

It occurs in a zone of faulting and fracture in shale rock, and the vein is len- 
ticular in form, occurring as a series of pockets of the general form, illustrated in 
Fig. 21, varying in thickness from a fraction of an inch to 30 ft. as a maximum. 
As the dip of the vein is very steep, the material must be hoisted out in 
buckets with a windlass, and then hauled 15 miles to Moyer, the nearest shipping 
point, at a cost of about S3. 00 per ton. Heavy timbering is necessary on account 
of the character of the enclosing rock. The grahamite shows the same variation 
in fracture and lustre as the Jackford Creek deposit. On analysis it tests as follows: 

Color in mass, fracture, lustre, specific gravity, hardness and behavior on heating in flame, same 
as the preceding: 

(Test 15) Fusing-point (K. and S. method) 460-520° F. 

(Test 16) Volatile matter, 500° F., 4 hrs Less than 1% 

(Test 19) Fixed carbon 48.5 -53.0% 

(Test 21o) Solubility in carbon disulphide 90.5 -96.2% 

(Test 216) Non-mineral matter insoluble 0.0- 6.0% 

(Test 21c) Free mineral matter 11- 6 . 7% 

(Test 22) Carbenes 68% 

(Test 23) Solubility in 88° naphtha 0.2-0.7% 

(Test 25) Moisture at 100° C 0.0 - 0.7% 

(Test 26) Carbon 83 90% 

(Te.st 27) Hydrogen 7. 14% 

(Test 28) Sulphur 1 . 04- 2. 24% 

Undetermined 6 . 72% 

(Test 33) Saturated hydrocarbons . 32% 

Atoka County. McGee Creek Deposits. Two small veins, one 4 in. and another 
about 1 ft. in thickness, occur in the SW i, Sec. 23, T 1 N, R 14 E, about 15 
miles northwest of Antlers. These constitute the so-called "WilHam's Mine." 
Shafts have been sunk from 15 to 20 feet, but not sufficient grahamite has been 
found to warrant continuing operations. It tests as follows: 

(Test 19) Fixed carbon 43 . 5-45 . 7% 

(Test 21a) Soluble in carbon disulphide 95 . 7-99 . 7% 

(Test 216) Non-mineral matter insoluble 0.0- 4.0% 

(Tost 21c) Free mineral matter 0.3% 

(Test 23) Soluble in 88° naphtha 4.5-6.8% 

A larger deposit also occurs in the vicinity of McGee Creek, in the NE |, 
Sec. 25, T 1 S, R 13 E, and NW i Sec. 30, T 1 S, R 14 E, about 12 miles 

* Further data on the fusing-points and hardness at various temperatures of mixtures of the 
grahamite with a Mexican residuum will be found in J. Ind. Eng. Chem., 7, 205, 1915, "Vari- 
ations of the Physical Characteristics of a Petroleum Residuum with Increasing Percentages of 
grahamite," by H. Rossbacher. 



ASPHALTITES 143 

southeast of Stringtown. This is known as the Pumroy or Moulton Mine. The 
grahamite fills a fissure, caused by faulting, and is reported to be 14 to 15 ft. 
thick at the surface, tapering to about 4 ft. at a depth of 110 ft. The mine is 
now abandoned, but when operated some years ago, about 2000 tons were mined 
annually, being hauled 15 miles to Stringtown, the nearest shipping point. A 
prospect occurs about | mile south of the foregoing, consisting of a vein about 2 
ft. thick. On analysis it tests as follows: 

(Test 15a) Fusing-point (K. and S. method) 473° F. 

(Test 19) Fixed carbon 38.42-41.0% 

(Test 21) Solubility in carbon disulphide 83.7 -95.0% 

(Test 216) Non-mineral matter insoluble 4.8-9. 2% 

(Test 21c) Free mineral matter . 98- 7.1% 

Boggy Creek Deposit. This occurs about 6 miles northeast of Atoka, and 1 
mile from the M. K. & T. R. R. in the SW I, Sec. 29, T 1 S, R 12 E. The 
vein occurs in shale varying in thickness from several inches to several feet. It 
has long been abandoned, and no analyses are available. 

Chickasaw Creek Deposit. An undeveloped vein in shale, carrying streaks of 
grahamite, about 9 ft. thick has been reported in Sec. 15, T 1 S, R 12 E about 
2 1 miles east of Stringtown on the M. K. & T. Railroad. 

Stephens County. This occurs in the NW i. Sec. 6, T 2 S, R 4 W, about 
6 miles north of Loco, and 18 miles east of Comanche. This vein has been pros- 
pected for about half a mile, and occurs as a fault in sandstone and shale. The 
vein is of a pronounced lenticular type existing in a series of pockets, some as 
large as 10 ft. across, often connected with a thin vein-like crack less than an 
inch wide. At several points the deposit pinches out entirely. In the direction 
of the vein, the pockets measure 25 to 100 ft. horizontally and vertically. A char- 
acteristic feature of this deposit is the infiltration of pyrites, grains of which are 
clearly visible to the naked eye. The surrounding shale is porous, and carries 
minute particles of the grahamite, which are disseminated throughout the rock 
for some distance on both sides of the vein.^ 

The material tests as follows: 

(Test 4) Fracture Hackly 

(Test 5) Lustre Dull 

(Test 6) Streak Black 

(Test 15a) Fusing-point (K. and S. method) : . . . 401-406° F. 

(Test 19) Fixed carbon 34.4 -39.4% 

(Test 21a) Soluble in carbon disulphide 81.85-97.70% 

(Test 216) Non-mineral matter insoluble 0.10- 3 . G0% 

(Test 21f) Free mineral matter (mostly pyritfs) 2. 20-14 . 55% 

Colorado 

Grand County. Deposits of grahamite are found in Middle Park along the 
continental divide in the northern part of Grand County. A large vein occurs 
in Sec. 24, T 4 N, R 77 W, on a fork of Willow Creek about 25 miles north of 
Grand River, in a region of clay, conglomerate and sandstone. Several veins and 
fissures have been prospected, the main vein varying in width from 2 ins. up to 
6 ft., and extending 100 to 125 ft. Comparatively small quantities of the gra- 

1 W. R. Crane, Mines and Minerals, Jan., 1906, 



144 ASPHALTS AND ALLIED SUBSTANCES 

hamite have been mined, due to difficulties in transportation to the nearest rail- 
road. The product tests: 

(Test 7) Specific gravity at 77° F 1 . 15- 1 . 16 

(Test 19) Fixed carbon 47.4 -49.3% 

(Test 21a) Soluble in carbon disulphide 98.2 -99.3% 

(Test 216) Non-mineral matter insoluble 0.6-1.7% 

(Test 21c) Free mineral matter. 0.0 - 0.1% 

(Test 22) Carbenes 80. 6% 

(Test 23) Solubility in 88° naphtha 0.8-1.3% 

(Test 26) Carbon , 85.9 -86.1% 

(Test 27) Hydrogen 7.63- 7.75% 

(Test 28) Sulphur 0.93- 0.99% 

Undetermined 5.34- 5.45% 



Mexico 

Province of Vera Cruz. A vein of grahamite has been found at Huasteca 
on the Panuco River ^ in a vertical fissure, occurring in shales with an overflow 
at the junction of the shale stratum with the overlying sandstone. On analysis the 
material tests as follows: 

(Test 7) Specific gravity, at 77° F 1 . 145 

(Test 19) Fixed carbon 35 . 3% 

^Test 21a) Soluble in carbon disulphide 93 . 8% 

(Test 216) Non-mineral matter insoluble 3.4% 

(Tes* 21c) Free mineral matter 2.8% 

(Test 23) Solubility in 88° naphtha 8.4% 

Province of Tamaulipas. Another deposit has been reported near the City of 
Victoria, containing 3.4 per cent of non-mineral matter insoluble in carbon disul- 
phide and 54 per cent of fixed carbon. 

Cuba 2 

Province Pinar del Rio. In the District of Mariel, near the City of Bahia 
Honda, there occurs a fairly large vein of grahamite, known as the "La America 
Mine," or the '"Rodas Conception Mine," testing as follows: 

(Test 4) Fracture Shows distinct 

cleavage veins 

(Test 5) Lustre Semi-dull 

(Test 7) Specific gravity, at 77° F 1 . 157 

(Test 19) Fixed carbon 40.0-42.2% 

(Test 21o) Soluble in carbon disulphide 99 . 4-99 . 6% 

(Test 216) Non-mineral matter insoluble 0.0-0.1% 

(Test 21c) Free mineral matter 0.4- 0.5% 

(Test 22) Carbenes About 25% 

Another deposit occurs near the City of Mariel, 1 mile south of Mariel Bay, 
known as the "Magdalena Mine," which extends about 100 ft. in length and 40 
ft. in width. Large quantities of asphalt have been mined from this deposit, which 

»Am. J. Sci., 12, 277, 1876. 

2 "Bitumen in Cuba," by T. Wayland Vaughan, Eng. Mining J., 73, 344, 1902; "An Examination 
of Some Bituminous Minerals," by F. C. Garrett, J. Soc. Chcm. Ind., 31, 314, 1912. 



ASPHALTITES 145 

is characterized by the presence of about 40 per cent of associated mineral matter. 
It tests: 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Dull 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity, at 77° F 1.41 -1.46 

(Test 19) Fixed carbon 30.0 -38.0% 

(Test 21a) Soluble in carbon disulphide 55 -58% 

(Test 216) Non-mineral matter insoluble 3 - 5% 

(Test 21c) Free mineral matter 38 -41% 

(Test 22) Carbenes 1.5- 6.3% 

(Test 23) Solubility in 88° naphtha 37 -48% 

(Test 26) Carbon 72.5 -77.8% 

(Test 27) Hydrogen 8.5 - 8.7% 

(Test 28) Sulphur 6.9 - 7.7% 

Difference 6.6 -11.4% 

Another vein occurs in this same locaHty, probably a continuation of the pre- 
ceding, knov/n as the "Mercedes Mine," testing similarly. 

Province of Havana. In the neighborhood of Campo Florida, grahamite has 
been obtained from a mine known as "La Havana," which tests: 

(Test 4) Fracture Semi-conchoidal 

(Test 5) Lustre Dull 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity at 77° F 1 . 175 

(Test 19) Fixed carbon 45 . 0% 

(Test 21a) Soluble in carbon disulphide 98.9% 

(Test 216) Non-mineral matter insoluble , 0.7% 

(Test 21c) Free mineral matter . 4% 

(Test 23) Solubility in 88° naphtha 6.0% 

(Test 26) Carbon 82 . 5% 

(Test 27) Hydrogen 7.5% 

(Test 28) Sulphur 6.4% 

Undetermined 3 . 6% 

A similar deposit has been reported about 12 miles east of Havana and another 
one, known as the "Casitalidad Mine," situated about 9-10 miles east of Havana, 
and 2 miles south of the coast, in a vein 600-900 ft. long and 1-30 ft. thick 
testing substantially the same as the preceding. 

Province of Santa Clara. Nine miles northeast of the Gity of Santa Clara 
near Loma Cruz, there occurs the deposit known as "Santa Eloisa," in a bed of 
serpentine. It tests as follows: 

(Test 4) Fracture Semi-conchoidal 

(Test 5) Lustre Bright 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1 . 29 

(Test 19) Fixed carbon 34-35% 

(Test 21a) Soluble in carbon disulphide 78-79% 

(Test 216) Non-mineral matter insoluble 1.8-2.2% 

(Test 21c) Free mineral matter 19 -20% 

(Test 22) Carbenes 2 -3% 

Another mine occurs a short distance from Placetas del Sur, in an irregular 
vein of lenticular form, occurring in several branches. This mine is known as the 



146 ASPHALTS AND ALLIED SUBSTANCES 

"Esperanza," and the product is characterized by its comparatively low fusing- 
point. The average material as mined tests as follows: 

(Test 4) Fracture Hackly 

(Test 5) Lustre Moderately bright 

(Test 6) Streak Black 

(Test 7) Specific gravity, at 77° F 1 . 22 

(Test 9a) Hardness, Moh's scale 2 

(Test 146) In flame Softens, splits and burns 

(Test 15a) Fusing-point (K. and S. method) 400-433" F. 

(Test 19) Fixed carbon 50 . 95% 

(Test 21a) Soluble in carbon disulphide 97.9-98.8% 

(Test 216) Non-mineral matter insoluble 0.05- 0.92% 

(Test 21c) Free mineral matter 1 . 15- 2.75% 

(Test 366) Mineral matter combined with non-mineral con- 
stituents 0.37% 



Trinidad 

Two deposits of grahamite^ occur near San Fernando on the west coast of the 
island on the shore of the Gulf of Paria, known as the Vistabella and Marbella 
Mines. The grahamite has been marketed under the name of "manjak," pre- 
sumably taking advantage of the popularity of the Barbados glance pitch, although 
from a geological standpoint the two minerals are entirely different. The veins 
occur in soft shale and sandstone, in a region carrying petroleum in considerable 
quantities. 

A number of veins of grahamite have been uncovered, the largest known as 
the Vistabella mine, which measures 360 ft. horizontally and has been mined to 
a depth of about 250 ft. Its thickness is 11 ft. at the outcrop, and increases 
steadily to 33 ft. at a depth of 200 ft. " Three distinct types have been found in the 
vein, viz.: 

(1) An amorphous coaly type which has a hackly fracture, and usually occurs 
at the margin of the vein. It is dull in lustre and exhibits no regular jointings. 

(2) A columnar type, of dull lustre, having a columnar jointing running at 
right angles to the margins of the vein. The jointing is often very well formed, 
dividing the material into hexagonal or pentagonal prisms. 

(3) A lustrous variety identical in appearance to gilsonite and Barbados glance 
pitch (manjak). This has a bright lustre, and a conchoidal fracture, being found 
in the deeper workings of the mine, in the centre of the vein. 

There is no chemical difference in the varieties, although it appears that at 
the centre of the vein at a depth of about 120 ft. the grahamite has a lower 
fusing-point, closely resembling the Barbados glance pitch, thus serving as a link 
between the grahamite and the glance pitch, clearly proving that both are derived 
by metamorphosis from a common source. 

A stratum of oil-bearing sandstone is known to exist beneath the grahamite 

i"The San Fernando Manjak Field," Council Paper No. 3, 1905, Council Paper No. 35, 1906, 
Council Paper No. 130, 1906, by the Government Geologist, Port-of-Spain, Trinidad; "Manjak as 
Worked at the Vistabella Mme, Trinidad," by J. C. T. Raspass, Trans. Inst. Mining Eng., Newcastle- 
upon-Tyne, Sept. 7, 1908; "An Examination of Some Bituminous Minerals," by F. C. Garrett, J. Soc. 
Chem. Ind., 31, 314, 1912. 



ASPHALTITES 147 

which appears more than hkely to have been derived from an asphaltic petroleum 
which intruded under pressure through a fault in the shale. 

The mining of the grahamite is comparatively simple, but the shafts have to 
be carefully timbered, and precautions have to be taken to avoid igniting the 
gases generated in the workings, as these are highly explosive. It is reported that 
betw^een 2000 and 2500 tons are mined per annum. 

On analysis it tests as follows: 

(Test 1) Color in mass Black 

(Test 2) Homogeneity 3 distinct types recog- 
nizable (see above) 

(Test 4) Fracture Types 1 and 2, hackly; 

Type 3 conchoidal. 

(Test 5) Lustre Types 1 and 2 dull; 

Type 3 bright 

(Test 6) Streak Black 

(Test 7) Specific gravity, at 77° F 1 . 170-1 . 175 

(Test 9a) Hardness, Ivloh's scale 2 

(Test 96) Hardness, penetrometer 

(Test 146) On heating in flame Softens, splits and burns 

(Test 15a) Fusing-point (K. and S. method) 350-438° F. 

Note. The material resembling glance pitch obtained from the centre of the vein at the 
200-ft. level fused at 280° F. (K. and S. method). 

(Test' 156) Fusing-point (B. and R. method) 370-460° F. 

(Test 19) Fixed carbon 31.5-35.0% 

(Test 20) Distillation test: 

Below 150° C 0.5% 

150-300° C 26.5% 

Above 300° C 18.0% 

Carbonaceous residue 55 . 0% 

Total 100.0% 

(Test 21a) Solubility in carbon disulphide 91.7-96.0% 

(Test 216) Non-mineral matter insoluble 0.9- 1.2% 

(Test 21c) Free mineral matter 4.0- 6.4%, averaging 

about 5.7% 

(Test 22) Carbenes About 40% 

(Teat 23) Solubility in 88° naphtha: 

At 100-ft. level 12.8% 

At 140-ft. level 15.2% 

At 200-ft. level 18.5% 

At 200-ft. level, softer material in centre 56.0% 

(Test 25) Moisture 0.2 - 1.0% 

(Te.st 26) Carbon 84.0% 

(Test 27) Hydrogen 5.7% 

(Test 28) Sulphur .' 3.0-3.8% 

(Test 29) Nitrogen 2.2% 

(Test 366) Mineral matter combined with non-mineral con- 
stituents 1 . 15% 

Fig. 54 shows the hardness, tensile strength (multiplied by 10) and ductility 
curves of a mixture of the grahamite fusing at 400° F. (K. and S. method), 
and residual oil (the same as utihzed in mixture shown in Fig. 53). fluxed 
together in such proportions that the hardness at 77° F. is exactly 25.0. The 



148 



ASPHALTS AND ALLIED SUBSTANCES 



resulting mixture contained grahamite, 32 per cent and residual oil, 68 per cent, 
and had a fusing-point of 200° F. (K. and S. method). 

The Marbella vein is smaller than the Vistabella, attaining a thickness of 7 ft. near 
its centre. It is lenticular in form and splits up into two smaller vems at one 



100 
90 
60 
70 

eo 

50 
40 
30 
20 
10 
0, 



32^ 



77^ 



115^ 

























- Hardness 




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^>. 
















— — 1 ensue o> jrengrn x lu \ 

^ [),i/-tii;+„ \ 




'""'." '-^.^^o^ 




\ 


V 


141 


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© Fusing KOI nT-zi/UT. . 
SuscepTibiliTy Factor= 21. $ 






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^v. 


\^ 






















. 






^^ 


1 


p 


"^^ 


^N 






























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45.0 

K 




























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.- 





.- 


400 






10.0 

1 


~^ 


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10 10 10 40 50 eo 70 80 90 100 llO 120 130 140 150 100 
Temperature, Degrees Fahrenheit 



Fig. 54. — Chart of Physical Characteristics of Fluxed Trinidad Grahamite Mixture. 



end. The grahamite mined from the Marbella vien has substantially the same 
characteristics as the preceding. At the 50-foot level 8.8 per cent is soluble in 
88° naphtha (Test 23) at the 125-ft. level, 9.6 per cent, and at the 200-ft. level 
12 per cent. 



CHAPTER XI 



ASPHALTIC PYROBITUMENS 



The asphaltic pyrobitumens are natural substances composed of 
hydrocarbons, characterized by their infusibiUty and comparative freedom 
from oxygenated substances. They are grouped into five classes, viz.: 
elaterite, wurtzilite, albertite, impsonite, and asphaltic pyrobituminous 
shales. The first four are comparatively free from associated mineral 
matter (usually under 10 per cent). If the mineral matter predominates, 
the material is known as an asphaltic pyrobituminous shale, which term 
is appHed indiscriminately to shales containing wurtzilite, albertite or 
impsonite. 

Much confusion exists regarding the classification of asphaltic pyro- 
bitumens. Every now and then it is alleged that some new type is 
discovered, which on closer investigation proves to be an old substance 
christened under a different name. Thus the so-called " nigrite " de- 
scribed by E. H. Eldridge,^ is nothing more than albertite (see p. 155). 

Elaterite, wurtzilite, albertite and impsonite when they occur asso- 
ciated with less than 10 per cent of mineral matter, are distinguished 
from one another as follows: 





Streak. 


Specific Gravity 
at 77° F. 


Fixed Carbon, 
Per Cent. 


Elaterite 


Light Brown 
Light Brown .... 
Brown to Black 
Black 


0.90-1.05 
1 . 05-1 . 07 
1.07-1.10 
1.10-1.25 


2-5 


Wurtzilite 


5-25 


Albertite 


25-50 




50-85 







All four are derived from the metamorphosis of petroleum, and it is 
probable that the impsonite represents the final stage of transformation 
of elaterite, wurtzilite and albertite, as well as the asphaltites (gilsonite, 
glance pitch and grahamite) . 



1 " The Asphalt and Bituminous Rock Deposits of the United States," 22d Annual Report, U. S. 
Geol. Survey, Wash., D.C. Part I, pp. 222 and 360, 1901. 

149 



150 ASPHALTS AND ALLIED SUBSTANCES 

ELATERITE 

This asphaltic pyrobitumen is the prototype of wurtzihte. It is found 
in a few locahties, in small amounts and is of scientific interest only. 

England 

Derbyshire County. Elaterite was originally discovered at the Odin Mine in 
Castleton by Lister in 1673-4 J It was again described by Hatchett,' who found 
it to be moderately soft and elastic, like India rubber, having a specific gravity 
of 0.9053-0.988. It is slightly soluble in ether (18 per cent) and swells up in 
petroleum naphtha. Klaproth ^ examined this same material, stating that it "fuses 
at a high heat, and after this may be drawn into threads between the fingers," 
also that it contains between 6 and 7 per cent of ash.'* 

Australia 
State of South Australia 

Coorong District. A variety of elaterite is found on the coast south of Ade- 
laide, Australia, known under the name of "coorongite." * 

Asiatic Russia 
Province of Semiryechensk 

This deposit occurs at the mouth of the Hi River, in the neighborhood of Lake 
Balkash,^ and tests as follows: 

(Test 7) Specific gravity 0.995 

(Test 21a) Solubility in carbon disulphide Very slight 

(Test 21c) Free mineral matter 3-5% 

(Test 37a) Acid value 4.9 

(Test 376) Saponification value 56.9 

(Test 39) Saponifiable matter 11.1 

Unsaponifiable matter 88.9% 

It is characterized by the presence of saponifiable matter, and in this respect differs from the 
foregoing. 

WURTZILITE 

This has been found in but one region/ as follows: 

United States 
Utah 

Uinta County. This region embraces about 100 square miles in 
the neighborhood of Indian, Lake, Avintequin and Sams Canyons, trib- 

i Phil. Trans., 1673. 

!^ Linn. Trans., i, 146, 1797. 

3 Beitr., 3, 107, 1802. 

* Morrison, Min. Mag., 8, 133, 1889; and Maguire, Mines and Minerals, 20, 398, 1900. 

5 Jackson, Pharm. J., 31, 763 and 785, 1872; G. C. Morris, Proc. Acad. Philad., 131, 1877; 
Gumming, Proc. Royal Soc. Vict., 15, 134, 1903; Boodle, Bull. Roy. Bot. Gardens, Kew, 145, 1907. 

6 Rakusin, Petroleum, 8, 729, 1913. 

iW. P. Blake, Eng. Mining J., 48, 542, 1889; 49, 59, 1890; also 106; Trans. Am. Inst. 
Mining Eng., 18, 497, 1889. 



ASPHALTIC PYROBITUMENS 



151 



utaries of Strawberry Creek, which in turn leads into the Uinta River. 

The veins occur about 50 miles southwest of Fort Duchesne, varying in 

length from several hundred feet to 

about 3 miles, and from 1 to 22 in. wide, 

filHng vertical faults in shaly limestone. 

Altogether about 30 veins have been 

discovered, closely resembhng those of 

gilsonite. Many of them spht into a 

number of smaller branches, either in a 

vertical or horizontal direction. The 

largest veins occur between the Left- 

Hand and the Right-Hand forks of 

Indian Canyon. It has been exploited 

under various names, including elaterite 

(improper use of this name), aegerite, 

aeonite, etc. 

A view of one of the veins is shown 
in Fig. 55; a section through the mine, 
in Fig. 56; and the tramway for con- 
ve}dng the product from the hillside 
mine to the valley below, in Fig. 57. 

Wurtzilite is characterized by being 
sectile and cutting Uke horn or whale- 
bone. Thin flakes are somewhat elastic, 
comparable in a way to that of glass or 
mica, rather than to the yielding elasticity 
of rubber. If a shaving is bent too far 

or suddenly, it snaps off like glass. This distinguishes it from other 
asphaltic pyrobitumens as well as the asphalt ites. 

Attempts were made to find its fusing-point by heating it as high as 
800° F. in sulphur, but without having any effect. 

It tests as follows: 




Courtesy of Raven Mining Co. 
Fig. 55. — View of Wurtzilite Mine, 
Uinta County, Utah. 



(Test 1) Color in masa Black 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Bright 

(Test 6) Streak Light brown 

Extremely thin splinters are semi-transparent, showing a 
deep red color by transmitted light. 

(Test 7) Specific gravity at 77° F 1 .05-1 .07 

(Test 9a) Hardness, Moh's Scale Between 2 and 3 

(Test 96) Hardness at 77° F. (penetrometer) 

(Test 9c) Hardness, consistometer, 77° F Over 150 

(Test 146) On heating in flame Softens and burns 

quietly 



152 



ASPHALTS AND ALLIED SUBSTANCES 




Courtesy of Raven Mining Co. 
Fig. 56. — ^Transporting Wurtzilite from the Mine, 




Courtesy of Raven Mining Co. 
Fig. 57.— Vertical Section through Wurtzilite Vein, Uinta County, Utah. 



ASPHALTIC PYROBITUMENS 153 

(Test 15) Fusing-point Does not fuse 

without decom- 
position 

(Test 16) Volatile at 325° F., in 7 hrs 1-3% 

(Test 19) Fixed carbon 5-25% 

(Test 20) Distillation test: 

0-150° C 16.15% 

150-200° C 21.70% 

200-250° C 2^.82% 

250-300° C 0.91% 

Carbonaceous residue . 36.92% 

(Test 21a) Soluble in carbon disulphide 5 -10% 

(Test 216) Non-mineral matter insoluble 85 -95% 

(Test 21c) Mineral matter 0.2- 2 . 5% 

(Test 22) Carbenes 0.0- 1.5% 

(Test 23) Soluble in 88° naphtha 0-2% 

(Test 24) Grams soluble in 100 grams cold solvent: 

Amyl acetate Insoluble 

Amyl alcohol Insoluble 

Amyl nitrate Insoluble 

Aniline Insoluble 

Benzol Insoluble 

Carbon tetrachloride 1.8 

Chloroform 1 

Ethyl acetate Insoluble 

Ethyl alcohol Insoluble 

Ethyl ether Insoluble 

Naphtha 62° 2.8 

Nitrobenzine Insoluble 

Propyl alcohol Insoluble 

Toluol 0.1 

Turpentine 45 

(Test 26) Carbon 79.5-80.0% 

(Test 27) Hydrogen . 10.5-12.5% 

(Test 28) Sulphur 4.0- 6.0% 

(Test 29) Nitrogen 1.8- 2.2% 

ALBERTITE 

This is a generic term applied to a group of asphaltic pyrobitumens 
similar to the type-substance which was formerly mined in Albert County, 
New Brunswick, Canada, characterized by its : 

(1) Infusibility; 

(2) Insolubility in carbon disulphide, etc.; 

(3) Specific gravity (1.07 to 1.10 at 77° F.); 

(4) Percentage of fixed carbon (25 to 50 per cent) ; 

(5) Small percentage of oxygen present (less than 3 per cent). 

It occurs in several localities, of which the typical deposit will be 
described first. 

Canada 
Province of New Brunswick 

County of Albert. In 1849 a local geologist, Dr. A. Gesner, discovered 
a substance originally termed " albert coal," subsequently renamed 



154 ASPHALTS AND ALLIED SUBSTANCES 

" albertite/'^ on Frederick Brook, a branch of Weldon Creek, near Albert 
Mines, 20 miles south of Moncton. Shortly after this, litigation gave rise 
to a discussion whether or not the mineral was a true coal. The courts 
decided that it was, and not until many years later was its true status 
determined. 

The principal vein has been traced approximately 2800 feet and 
varies in thickness from several inches to a maximum of 17 ft. It is 
connected with a number of smaller lateral veins which in turn break up 
into still smaller offshoots. The maximuni depth reached by mining 
operations was approximately 1400 ft., and it is estimated that alto- 
gether 230,000 tons have been mined. The main use of the product was 
to enrich bituminous coal in the manufacture of illuminating gas, but it 
is no longer available, as the mine has been inactive for many years. 

This occurrence takes the form of a true fissure vein cutting across a series of 
beds of so-called "oil shales," which will be described in greater detail later (see 
p. 162). Mention should be made here that the surrounding shales abound in fossil 
remains of fish, which indicate that albertite and its associated shales are of animal 
origin. 

On analysis it tests as follows: 

(Test 1) Color in mass Black 

(Test 2) Homogeneity Uniform 

(Test 4) Fracture Conchoidal to hackly 

(Test 5) Lustre Bright 

(Test 6) Streak Brown to black 

(Test 7) Specific gravity at 77° F 1.075-1.091 

(Test 9a) Hardness, Moh's scale 2 

(Test 96) Hardness, penetrometer, 77° F 

(Test 9c) Hardness, consistometer, 77° F Greater than 150 

(Test 14c) On heating in flame Intumesces 

(Test 15) Fusing-point Infusible. Decomposes 

before it melts 

(Test 19) Fixed carbon . 25 -50% 

(Test 21o) Soluble in carbon disulphide 2 -10% 

(Test 216) Non-mineral matter insoluble 85 -98% 

(Test 21c) Mineral matter 0.1- 0.2% 

(Test 23) Soluble in 88° naphtha 0.5-2.0% 

(Test 24) Solubility in pyridine (boiling) 25 -35% 

I II III IV V 

(Test 26) Carbon 83.44% 85.40% 85.53% 86.31% 87.25% 

(Test 27) Hydrogen 10.08 9.20 13.20 8.96 9.62 



(Test 28) Sulphur 0.44 Trace 1 . 20 Trace 

(Teat 29) Nitrogen 3.10 0.42 2.90 1.75 

(Test 30) Oxygen 2.22 1.97 

Undetermined. 6.04 0.12 0.10 1.21 



100.00% 100.04% 100.35% 100.24% 99.83% 

iC. T. Jackson, Proc. Boston Sac. Nat. Hist., 3, 279; Wetherill, Trans. Am. Phil. Soc, Philad., 
353, 1852; "Albertite," Dr. J. W. Dawson, F.G.S., "Acadian Geol." Edinburgh, p. 198, 1865; 
"Albertite," C. H. Hitchcock, Amer. J. Sci., 39, pt. 2, 267, 1865; W. P. Blake, Trans. Am. Inst. 
Mining Eng., 18, 563-82, 1889; Milner, J. Mining Soc. Nova Scolia, 17, 62, 1912; "Oil Shales of 
America," by C. Baakerville and W. A. Hamor, J. Ind. Eng. Chem., 1, 507, 1909; 6, 73, 1913. 



ASPHALTIC PYROBITUMENS 



155 



Province of Nova Scotia 

Pictou County. An unusual deposit occurs immediately below the well-known 
McGregor seam at Stellarton. The approximate thickness of the bed is given as 
5 ft., subdivided as follows: 

(1) A layer of coal 1 ft. 4 in. wide. 

(2) A layer of albertite 1 ft. 10 in. wide. 

(3) A layer of pyrobituminous shale 1 ft. 10 in. wide. 

The species of albertite has been exploited under the name "stellarite." It 
seems to represent a state of transition between true albertite and the cannel 
coals, of which the Scotch mineral torbanite (see p. 160) is a representative. The 
bed contains fossil animal and vegetable remains. A splinter of stellarite may be 
easily lighted with a match and will burn with a bright, smoky flame, throwing off 
sparks like stars (whence its name). It was formerly used to enrich bituminous 
coals in the manufacture of illuminating gas. The layer of coal is an ordinary 
fat-coking coal, showing a laminated structure, and containing 62.09 per cent of 
fixed carbon and 4.33 per cent of ash. 

The stellarite and associated pyrobituminous shale tests as follows: 



(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 



Color in mass. . 

Fracture 

Lustre 

Streak 

Specific gravity 
Fusing-poijit . . . 
Fixed carbon. . . 



1) 

4) 

5) 

6) 

7) 
15) 
19) 
21a) Soluble in carbon disulphide 



77° F. 



21c) 
25) 
26) 
27) 
28) 
29) 
30) 



Mineral matter. 

Moisture 

Carbon 

Hydrogen 

Sulphur 

Nitrogen 

Oxygen 



Stellarite (albertite) 
Brown to black 
Hackly 

Semi-bright to dull 
Reddish brown 
1.07-1.10 
Infusible 
22.35-25.23% 

2.0% 

8.2 -8.9% 

0.2 -0.3% 
88.1% 
11.1% 

0.1% 

0.2% 

0.5% 



Pyrobituminous shale 
Gray black 
Conchoidal 
Dull 
Brown 
1 . 56-1 . 78 
Infusible 

8.3 -12.3% 
Trace 
52.0-62.0% 

0.6- 1.0% 



0.25-0.74% 



The presence of the very small percentage of oxygen (0.5 per cent) differentiates 
the material from lignite and the other non-asphaltic pyrobitumens, thus corre- 
sponding with the ultimate analysis of the New Brunswick albertite. 



United States 
Utah 

Uinta County. A vein of albertite (christened "nigrite" by Eldridge, see p. 
140), 120 ft. long, showing a maximum width of 20 in., is found 8 miles from Helper, 
and 5 miles east of Soldier Summit, having the following characteristics: 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Semi-dull 

(Test 6) Streak Brownish black to black 

(Test 7) Specific gravity at 77° F 1 . 092-1 . 099 

(Test 9a) Hardness, Moh's scale 2 

(Test 146) Heating in flame Splits ^nd burns 

(Test 15) Fusing-point Infusible 

(Test 19) Fixed carbon 37 -40% 

(Test 21a) Soluble in carbon disulphide 3 -6% 



156 ASPHALTS AND ALLIED SUBSTANCES 

(Teat 216) Non-mineral matter insoluble 94.20-97% 

(Test 21c) Mineral matter 0.2% 

(Test 23) Soluble in 88° naphtha Trace 

(Test 28) Sulphur 1.0% 

Australia 

Tasmania. A species of albertite described under the name of "tasmanite"^ 
has been reported near the River Mersey in the northern portion of Tasmania. 
It is found disseminated in a pyrobituminous shale and compUes with the following 
tests: 

(Test 1) Color in mass Black 

(Test 2) Homogeneity Uniform 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre. . Bright 

(Test 6) Streak Yellowish brown 

(Test 7) Specific gravity at 77° F 1 . 10 

(Test 9a) Hardness, Moh's scale 2 

(Test 15) Fusing-point Infusible 

(Test 21a) Soluble in carbon disulphide Trace 

(Test 21c) Mineral matter 8 . 14% 

(Test 26) Carbon 79.2 -79.3% 

(Test 27) Hydrogen 7.2 - 7.4% 

(Test 28) Sulphur 5.28- 5.32% 

(Tests 29 and 30) Nitrogen and oxygen 4.93% 

West Africa 
Libollo 

A species of albertite is reported at this locality under the name "libollite." ^ 

IMPSONITE 

This represents the final stage in the metamorphosis of asphaltites 
and asphaltic pyrobitumens. It is characterized by its: 

(1) InfusbiHty and insolubiUty in carbon disulphide; 

(2) Specific gravity (1.10 to 1.25); 

(3) High percentage of fixed carbon (50 to 85 per cent) ; 

(4) Comparatively small percentage of oxygen (less than 5 per 

cent), which differentiates it from the non -asphaltic pyro- 
bitumens. 
The weathered asphaltities taken from the exposed portions of the 
vein, where they have been subjected for centuries to the action of the 
elements, closely resemble impsonite in their physical and chemical 
properties, and may therefore be classified as such. Outcrops of gra- 
hamite are especially prone to metamorphize into impsonite, and many 
prospectors have been misled on this account. 

lA. J. Church, Phil. Mag., 28, 465, 1864; Newton, Geal Mag., 2, 336, 1875; Stephens, Proc. Roy. 
Soc. Tas., 6, March, 1876. 

2 Gomes, Comm. Dir. Trabalhoa Oeol., Portugal, 3, 244-290; 4, 206, 1896-8. 



ASPHALTIC PYROBITUMENS 157 

The following represent the most important deposits : ^ 

United States 
Oklahoma 

La Flore County. One of the largest deposits of impsonite occurs 2 miles east 
of Page on the southern slope of Black Fork Mountain (S i Sec. 24, T 3 N, R 26 E), 
filling a fissure caused by a fault. The vein is about 10 ft. thick, and has been 
mined to some depth. It compHes with the following tests: 

(Test 1) Color in mass Black 

(Test 4) Fracture Hackly 

(Test 5) Lustre Semi-dull 

(Test 6) Streak Black 

(Test 7) Specifivc gravity at 77° F 1 . 235 

(Test 9o) Hardness, Moh's scale 2-3 

(Test 14b) Heating in flame Decrepitates 

(Test 15) Fusing-point Infusible 

(Test 19) Fixed carbon 75 . 0-81 . 6% 

(Test 21o) Soluble in carbon disulphide 4 -6% 

(Test 216) Non-mineral matter insoluble 93 -96% 

(Test 21c) Mineral matter 0.7- 2.5% 

(Test 24) Solubility in pyridine (boiling) 3 . 88% 

(Test 25) Moisture 0.1- 1.5% 

(Test 28) Sulphur 1 . 69% 

Murray County. Impsonite has been reported 5 miles northeast of Dougherty 
(Sec. 33, T 1 S, R 3 E), in a vein about 18 in. thick at the top and 7 ft. at the 
bottom. Its characteristics are similar to the preceding. 

Arkansas 

Scott County. Another deposit of Impsonite occurs in the western part of 
Fourche Mountain, about 12 miles east of the Black Fork Mountain locality in 
Oklahoma. The exact locality is 1 mile east of Eagle Gap, and 2 miles east of 
Harris. It occurs in a region of shale and sandstone, and tests as follows: 

(Test 1) Color in mass Black 

(Test 4) Fracture Hackly 

(Test 5) Lustre Semi-dull 

(Test 6) Streak Black 

(Test 7) Specific gravity at 77° F 1 . 25 

(Test 9a) Hardness, Moh's scale 3 

(Test 146) Heating in flame Decrcptitates 

(Test 15) Fusing-point Infusible 

(Test 19) Fixed carbon 80 . C% 

(Test 216) Non-mineral matter insoluble . 99 . 3% 

(Test 21a) Soluble in carbon disulphide Trace 

(Test 21c) Mineral matter 0.6% 

(Test 28) Sulphur 1 . 38% 

Nevada 

Eureka County. A deposit is reported 15 miles scuth of Palisade in Pine Creek 
valley, in a vein filling a fault about 300 ft. long and of unknown depth. Its 
physical and chemical characteristics are similar to the preceding. ^ 

•"Grahamite Deposits Found in Eastern Oklahoma," by J. A. Taff, Bulletin No. 380, U. 
S. Geol. Survey, Wash., D. C, p. 295, 1909. 

2 "An Occurrence of Asphaltite in Norxheastern Nevada," by Robert Anderson, Bulletin No. 
380, U. S. Geol. Survey, Wash., D. C, p. 283, 1909. 



CHAPTER XII 
PYROBITUMINOUS SHALES 

Under this heading will be considered the oil-forming shales con- 
taining pyrobitumens associated with earthy matter, which will produce 
oily or tarry distillates upon being subjected to destructive distillation. 
Oil-hearing and asphalt-hearing shales from which petroleum or asphalts 
may be extracted with solvents are not included. The well-known 
shales in France occurring at Autun (Saone-et-Loire) and Bruxieres-les- 
Mines (Allier) consisting of semi-liquid asphalt associated with shales 
shall accordingly be excluded, although these have been classified indis- 
criminately with the true pyrobituminous shales by other writers. 

Pyrobituminous shales may be sub-divided into two classes: 

(1) Asphaltic pyrobituminous shales in which asphaltic pyro- 
bitumens (elaterite, wurtzilite, albertite or impsonite) are associated with 
shales. 

(2) Non-asphaltic pyrobituminous shales in which non-asphaltic 
pyrobitumens (cannel coal, lignite or bituminous coal) are associated 
with shales. 

Little or no attempt has been made to differentiate between these two 
groups, on account of the difficulty in identifying the bituminous material 
present. This will become apparent when it is considered that pyro- 
bitumens are substantially insoluble in solvents and are moreover masked 
by the associated mineral matter, which interferes with the usual dis- 
tinguishing tests, such as the specific gravity, lustre, streak, etc. Up 
to the present time all pyrobituminous shales have been referred to under 
the general term '' oil shales," which is really a misnomer. 

The following means are suggested to differentiate the two classes : 

(1) By the pyrobitumens found locally. 

The presence of asphaltic bitumens in the vicinity would indicate an 
asphaltic pyrobituminous shale. Similarly, non-asphaltic pyrobitumens 
would tend to establish the identity of the shale as non-asphaltic. If 
both types are present, the evidence is non-conclusive. 

(2) By the associated fossil remains. 

If vegetable (plant) fossil remains only are found associated with the 

158 



PYROBITUMINOUS SHALES 



159 



shale, the indications are that it is non-asphaltic, since it is definitely 
estabhshed that the non-asphaltic pyrobitumens are of vegetable origin. 
On the other hand, if animal (fish or mollusc) fossil remains are present, 
the shale will more than likely represent the asphaltic pyrobituminous 
variety. 

(3) Effect of heat on the solubility, — 

On heating in a closed retort to 300 to 400° C, asphaltic pyro- 
bituminous shales will depolymerize and become more soluble in carbon 
disulphide (see p. 57), whereas the non-asphaltic pyrobituminous shales 
remain unaffected. 

(4) By the percentages of fixed carbon and oxygen (calculated on 
the basis of the non-mineral matter present). These two criteria, con- 
sidered together, furnish the most reliable means of distinguishing 
between the two classes of shale, as will be observed from the following 
figures, calculated on the basis of the non-mineral constituents present: 





Per Cent Fixed 

Carbon (Calculated 

on the Mineral-free 

Basis). 


Per Cent Oxygen 
(Calculated on the 
Mineral-free Basis). 


Asphaltic Pyrobituminous Shales: 

W^urtzilite shales 


2-10 
5-25 

5-20 
15-30 
25-50 


T.pqq tVia-n 9 


Albertits shales 


Less than 3 

m' 

5 10 


Non-asphaltic Pyrobituminous Shales: 

Cannel coal shales 


Lignite shales . 


15 28 


Bitunijnous coal shales 


3 18 







It will be noted that the percentage of fixed carbon calculated on the 
mineral-free basis, runs lower than in the corresponding (pure) pyro- 
bitumens (see p. 60 and p. 483), due to the presence of the mineral 
matter, which assists in the combustion of the carbon during the test, 
decreasing the yield of '' fixed carbon," and at the same time increasing 
the percentage of volatile constituents. This is important from a com- 
mercial view-point. The most valuable pyrobituminous shales are those 
which produce the largest amount of volatile matter when subjected to 
destructive distillation. This is true with the albertitic cannel coal 
(torbanitic) and lignitic shales, whereas the bituminous coal shales 
yield but little volatile matter and have no commercial importance. 
Two types of bituminous constituents are present in non-asphaltic pyro- 
bituminous shales, viz.: (1) macerated and carbonized plant remains 
similar to -coal, and (2) yellow resinous bodies representing the last stage 



160 ASPHALTS AND ALLIED SUBSTANCES 

in the oxidation of the woody tissue.^ Elateritf^, wurtzilite and impsonite 
shales are rarely found. 

Before taking up the shales proper, we will first consider the proto- 
substances of the cannel-coal shales, namely the " cannel '* or " parrot 
coals " (called so on account of the crackling noise taking place on com- 
bustion), of which '' torbanite '^ and '' pyropissite " are the best known 
examples. These represent the pure bituminous constituents as they 
occur in the respective shales, and accordingly furnish a valuable in- 
sight into the composition of the shales themselves. (See p. 60.) 

Torbanite is now extinct, but was mined in large quantities at Torbane Hill, 
near Bathgate in Linlithgowshire, Scotland, from 1850 to 1862. It is also known 
under the names "torbanehill mineral," "boghead cannel coal," and "bathvillite," and 
tests as follows: 

(Test 1) Color in mass Brown to nearly black 

(Test 2) Homogeneity Uniform and amorphous 

(Test 4) Fracture Sub-conchoidal 

(Test 5) Lustre Dull 

(Test 6) Streak Yellowish 

(Test 7) Specific gravity at 77° F 1 . 17-1 . 32 

(Test 9a) Hardness, Moh's scale 2 

(Test 146) Heating in flame Ignites, splits and burns 

(Test 15) I*using-point Infusible 

(Test 19) Fixed carbon 6.6-13.3%; 

average 7.65% 

Same calculated on non-mineral matter 9.6% 

(Test 21o) Soluble in carbon disulphide Slight 

(Test 21c) Mineral matter 12 . 8-23 . 2% 

(Test 23) Solubility in 88° naphtha Less than 1.5% 

(Test 26) Carbon 78.67-78.86% 

(Test 27) Hydrogen 11.11-11.46% 

(Test 28) Sulphur 0.50-0.70% 

(Test 29) Nitrogen 0.55-1.37% 

(Test 30) Oxygen. 9.68-10.22% 

Torbanite differs from the asphaltic pyrobitumens in its physical properties, also 
in containing a greater percentage of oxygen and because it shows distinct signs 
of having originated from plant growth. For many years there was much discus- 
sion regarding the exact status of torbanite, and whether or not it represented a 
true coal. 2 It probably represents a state of transition between vegetable matter 
and the true non-asphaltic pyrobitumens. The cannel or boghead shales found in 
the Lothians (Scotland) consist of bituminous substances of the nature of tor- 
banite (termed "kerogen" by the Scottish geologists) associated with more or less 
mineral matter. 

Pyropissite is a species of cannel coal, formerly mined at Weissenfels, near Halle, 
Saxony. It contains plant remains, showing unmistakable traces of the cellular 
tissue, and tests as follows: 

(Test 1) Color in mass Grayish brown 

(Test 2) Homogeneity Uniform 

1 H. R. J. Conacher, Geol. Mag., 4, 93, 1917. 

2 Watson Smith, J. Soc. Chem. Ind., 28, 398, 1909. 



PYROBITUMINOUS SHALES 161 

(Test 4) Fracture Semi-conchoidal 

(Test 5) Lustre Earthy 

(Test 6) Streak Yellowish-brown 

(Test 7) Specific gravity at 77° F. (dry material) 0.9-1.1 

(Test 146) Behavior on heating in flame Melts easily to a 

pitch-like mass 

(Test 19) Fixed carbon 10-15% 

(Test 21a) Solubility in carbon-disulphide (when dry) 60% 

(Test 216) Non-mineral matter insoluble 32.3% 

(Test 21c) Mineral matter 7.7-12,1% 

(Test 25) Water Variable; up to 50- 

60% 

(Test 26) Carbon 77.0% 

(Test 27) Hydrogen 12.6% 

(Test 28) Sulphur 0.2% 

(Test 29) Nitrogen 0.3% 

(Test 30) Oxygen 9.9% U' - 

Total 100.0% 

(Test 33) Paraffine 62% 

It will be observed that pyropissite contains a good proportion soluble in car- 
bon disulphide, i.e., the so-called montan wax (see p. 79), and may therefore 
be considered a "semi-pyrobitumen," falling on the border line between vegetable 
matter and non-asphaltic pyrobitumens. In the same way, the pyropissitic shales 
may be classified as "semi-pyrobituminous shales." On destructive distillation, pyro- 
pissite yields: gases 8-12 per cent, water 8-12 per cent, tar 64-66 per cent (specific 
gravity 0.84-0.91) and coke 12-26 per cent.i 

We will now consider the more important deposits of pyrobituminous shales 
throughout the world: 

United States 

Lignitic and bituminous coal shales ^ are found in the States of Ken- 
tucky (Breckenridge County), Virginia, Tennessee, north-western Colorado 
(in the neighborhood of the Green River), northwestern Utah, Missouri, 
Nevada (Humboldt River opposite Elko), Wyoming, Montana (Big 
Blackfoot River near Green Falls) and California (Cholame Valley north 
of Parkfield). 

The principal beds of pyrobituminous shale may be traced along a 
line from central Alabama, northeastward through Tennessee and Virginia, 
and thence westward across central Ohio, passing close to Columbus, 
reaching the Ohio River near Vanceburg. From this point, the shale 
makes a loop through central Kentucky, past Lebanon, extending to 
Louisville, from which it stretches in a broad belt northwestward across 

* Scheithauer, "Fabrikation der Mineralole:" p. 21. 

2 Second Rept., Geol. Surv., Kentucky, 7, 211, 1856; "Oil Shales of America," Baskerville and 
Hamor, /. Jnd. Eng. Chem., 507, 1909; "American Oil Shales," Baskerville and Hamor, 8th, 
Intern. Cong, of Appl. Chem., 25, 631, 1912; Day in "Mineral Resources of the United States," 
11, 1071, 1913; Woodruff and Day, Bull. 581-A, U. S. Geol. Surv., Wash., D. C, 1915; De 
Beque, Eng. Mining J., 99, 773, 1915; U. S. Comm. Rept., March 13, 1916; "Oil Resources of 
Black Shales of the Eastern U. S.," G. H. Ashley, Bull. 641-L. U. S. Geol. Surv., Wash., D. C, 
1917. 



162 ASPHALTS AND ALLIED SUBSTANCES 

Indiana, past Indianapolis, almost reaching Chicago. They are known 
as the Chattanooga, New Albany and Ohio Shales. 

Canada V 

Province of New Brunswick. Pyrobituminous shales, known as "albert shales," 
or "arcadian shales" (termed "oilite" by the local geologists) have a wide dis- 
tribution in Westmoreland, Albert and Kings counties. On destructive distillation 
these shales yield products similar to those derived from the distillation of albertite, 
and the composition of the non-mineral matter is supposedly similar to the latter. 
The albert shale series in places attains a thickness of about 1000 ft. and is made 
up principally of the shales themselves, associated with other inter-bedded sedi- 
mentaries. In color the shales may be either gray, dark brown or black. Certain 
varieties, such as the so-called "curly" shales, show a massive structure and break 
with a conchoidal fracture, while others have a laminated structure and separate 
readily into thin, flexible layers. In the massive varieties, veinlets of glossy black 
material, resembling albertite, are not uncommon. Fossil remains of fish abound, 
especially in the laminated varieties. 

The shales found at Turtle Creek in the neighborhood of Baltimore, Albert 
County, have the following composition: 

Moisture 0.36- 1.54% 

Ash 44.21-56.10% 

Fixed carbon 3.29- 5.05% 

Sulphur 1.04- 1.70% 

Ultimate analyses are not available, but there seems to be little question that 
the non-mineral matter closely resembles albertite. 

Province of Nova Scotia. Asphaltic pyrobituminous shales, also known as 
"arcadian shales," are found in Pictou and Antigonish counties. Some of the 
shales are of the asphaltic and others of tJie non-asphaltic pyrobituminous class. 
Of the former the so-called "stellarite shales" in Pictou (see p. 155) may be 
cited as an example. True coals are also found in this region, associated with coal 
shales (lignitic and bituminous). 

Newfoundland. Black bituminous shales occur on the north side of Notre 
Dame Bay, Cap Rouge Peninsular and in the neighborhood of Deer and Grand 
Lakes. These are probably of the nature of bituminous coal. Analysis of one 
specimen shows it to contain: 

Fixed carbon 35% 

Ash 29% 

Province of Quebec. Pyrobituminous shales, or shaly sandstones, occur on 
certain streams emptying into the Gaspe Basin, principally along the York and 
Dartmouth rivers. Thus far, these shales are of scientific interest rather than of 
commercial importance. Unlike the shales of New Brunswick, the bituminous con- 
stituents occur as small particles physically combined with rather fine-grained 
shaly sandstone bands. These particles are of a black or brown color, and show a 

1" Mineralogy of Nova Scotia," by H. How; Canadian Dept. of Mines for 1908, Bull. 1072, 
p. 132; Bull.^ 1120, p. 200, 1909; "Joint Report of the Bituminous Oil-shales of New Brunswick 
and Nova Scotia," Bulls. 55 and 1107, 1910; "The Oil Shales of the Maritime Provinces," by 
R. W. Ells, J. Mining Soc. Nova Scotia, 14, 1909-10. 



PYROBITUMINOUS SHALES 163 

pale yellow streak, conchoidal fracture, and vitreous lustre. The shales contain 
from 50 to 70 per cent of mineral matter, and yield 7 to 10 per cent fixed carbon. 
They are therefore probably of the asphaltic pyrobituminous variety. 

The so-called "Utica Shales" are found along the St. Lawrence River all the 
way from Quebec to Montreal. Farther west the shales may be traced along the 
Ontario Peninsula along the shore of Lake Ontario in the vicinity of Port Hope, 
continuing along the shore of Lake Huron near Georgian Bay, and particularly 
in the neighborhood of Collingwood. These contain about 90 per cent of mineral 
matter, the non-mineral constituents being probably of a ligneous character. 

Brazil 

Province of Bahia. Pyrobituminous shales of uncertain composition have been 
reported in the Camamu basin. ^ 

England 

A belt of pyrobituminous shales of the lignitic and cannel coal varieties (known 
as the Kimmeridge Shales) stretches from Dorsetshire acrosc to Lincolnshire and 
Norfolkshire in thin seams. ^ 

Scotland 

This is the home of the shale industry, which is still being worked very 
actively. The Scotch shales (known as " Lothian ") as at present worked 
occur in a well-defined area lying 12 miles west of Edinburgh on the south 
side of the Firth of Forth, from Hopetoun southwards for 16 miles to 
Cobbenshaw, varying in width from 3 to 8 miles. ^ They occur as a fine- 
grained, brownish, brownish black to black clay shale in the Upper Calcif- 
erous Sandstone Series, having a distinctly laminated fracture, a dull 
lustre, and a specific gravity at 77° F. of 1.75. Rich shales also occur 
on the north side of the Forth in Fifeshire; and in Edinburghshire and 
LinUthgowshire, strata of shales are found in the Lower Calciferous Sand- 
stone Series, not very rich, but which may nevertheless pay to work some 
day. The shales are divided into two classes known as " plain " and 
** curly " depending upon the predominence of the laminated structure. 
The best varieties are distinguished by being cut into thin shavings 
with a sharp knife without breaking. These shales may be classed as 
torbanitic, and are now mined in the following counties: 

Edinburghshire (mid Lothian). Pumpherston, Oakbank, New Farm, Roman Camp, 
Ingleston, Limefield, and Cousland. 

1 Branner, Trans. Am. Inst. Mining Eng., 30, 537, 1901. 

« "Kimmeridge Shale, Its Origin, History, and Uses," Burton Greene. London. 1886; "Pe- 
troleum and Its Products," Boverton Redwood, Vol. 1, 1st Edition, p. 14; Williams, J. Chem. 
Soc, 7, 97; Phil. Mag., 8, 209. 

3 "A Practical Treatise of Mineral Oils and Their By-products," by Iltyd Redwood. London, 
1897; "Oil Shales of the Lothians," Part I: "Geology of the Oil Shale Fields," by H. M. 
Cadell and I. S. Grant Wilson; Part II: "Methods of Working Oil Shales," by W. Caldwell; 
Part III: "Chemistry of the Oil Shales," by D. R. Steuart; issued by the Dept. of Minos, 
Geol. Survey, Scotland, 1906; Trans. Inst. Mining Eng., 22, 314 E, 1902; "The Shale Oil Indus- 
try," D. R. Steuart, J. Soc. Chem. Ind., 14, 774. 1916. 



164 ASPHALTS AND ALLIED SUBSTANCES 

Linlithgowshire (West Lothian). Broxburn, Dalmeny, Bathgate, Uphall, Philips- 
toun, Forkneuk, Addiewell, Hopetoun, Westwood, Deans, Seafield and Newliston. 



Fifeshire. Burntisland (now stopped). 
Lanarkshire. Tarhrax and Cobhinshaw. 
Stirlingshire. Blackrigg. 
Renfrewshire. 
Ayrshire. 



In these counties, in the early days of 
the industry, cannel coal and shales 
were mined from strata at a higher 
horizon than the Calciferous Sand- 
stone Series in the coal measures, 
but the deposits have since been ex- 
hausted. 



Germany 
Pyropissitic and lignitic shales are found in Rhenish Prussia, Saxony (in the 
so-called Halle District at Halle, Weissenfels, Zeitz, Aschersleben and Eisleben), 
Hesse (Messel near Darmstadt), Bavaria and Wittenberg (Reuthngen).^ 

Spain 

Shales pf uncertain composition occur in the Ronda District in the southern 
portion of Spain. 

Austria 
Lignitic shales are found in Moravia, Bohemia and in the Tyrol. 

Australia^ 

New South Wales. Here we find the coorangitic shale designated locally as 
"kerosene shale," the non-mineral portion of which corresponds to the asphaltic 
pyrobitumen coorangite (see p. 150), the joadja shale, the classification of which 
is questionable, afid the asphaltic pyrobituminous shales of the Wolgan and Capertee 
Valleys at Murrurundi, Torbane, Capertee, and Wolgan. 

New Zealand. Here the shales are reported to occur at Orepuki. 

Tasmania. 

Queensland. 

Victoria. 

From the foregoing it will be apparent that the subject of " pyro- 
bituminous shales " is an extremely complicated one, still requiring a vast 
amount of research work before all the deposits can be correctly classified. 

Pyrobituminous shales are treated exclusively by subjecting them 
to a process of destructive distillation in suitable retorts to recover the 
tarry distillate and ammonium sulphate as will be described in Chapter 
XVI. The intrinsic value of the shale is dependent upon the amount of 
shale tar and ammonium sulphate obtained. It is interesting to note in 
passing that Steuart obtained a product resembling crude shale oil upon 
subjecting a mixture of lycopodium spores and clay to destructive dis- 
tillation. 

* "Shale Oils, and Tars and Their Products," by Dr. W. Scheithauer. London, 1913. 

2 Annual Report Col. Mun. Lab. N. Z., 23, 50; 25, 56; 29, 19; 31, 10;. Petrie, J. Soc. Chem., 
Ind., 24, 996; Dunlop, Rept. Dept. Mines, N. Z., C 3, 52, 1900; "The Kerosene Oil-shales of 
New South Wales," J. E. Carne, 1903; Bull. Queen, Gov, Min. D., December 15, 1915. 



PART III 
TARS AND PITCHES 



CHAPTER XIII 

GENERAL METHODS OF PRODUCING TARS 

Tars constitute the volatile oilyde composition products obtained in 
the pyrogenous treatment of bituminous and other organic substances, 
and represent distillates of dark color, liquid consistency; having a char- 
acteristic odor; comparatively volatile; of variable composition; some- 
times associated with carbonaceous matter, the non-carbonaceous con- 
stituents being largely soluble in carbon disulphide; and whose distillate 
fractioned between 300 and 350° C. yields comparatively little sulphona- 
tion residue. The pyrogenous treatment embraces three processes, viz.: 

(1) Subjecting to heat alone without access of air, often termed 
" destructive distillation.'' 

(2) Partial combustion, which may take place either in an atmosphere 
of air and steam (i^n gas producers) or with a limited access of air. 

(3) Cracking oil vapors at high temperatures. 

Practically all organic substances which undergo decomposition 
upon being subjected to heat produce tars, provided they yield a sub- 
stantial proportion of volatile decomposition products, the temperature 
is sufficiently high to bring about the decomposition, and air is entirely or 
partially excluded during the pyrogenous treatment. If the organic 
substance does not contain volatile matter, as proves the case with 
anthracite coal or graphite, no tar will result. If air is present in too 
large a quantity, the products of decomposition will undergo complete 
combustion, and the tar will be consumed. Materials which evaporate 
(i.e. distil undecomposed) or sublime will remain unchanged in com- 
position, and products that explode are converted into permanent gases, 
without the formation of tars. 

165 



166 



ASPHALTS AND ALLIED SUBSTANCES 



At the present time tars are produced commercially from the following 
products: 

(1) Bituminous substances including peat, hgnite, bituminous coal, 
petroleum and pyrobituminous shales. 

(2) From certain other organic substances including wood, and 
bones. 

In the early days of the industry, tars were also produced during the 
destructive distillation of grahamite and albertite (see page 221). 

The following table will give a synoptical outline of the raw materials 
used, the modes of treatment, and the kinds of tar produced : 



TABLE XV. 





Heat Alone 
("Destructive 
Distillation"). 


Partial Combustion. 




Raw Materials Used. 


Air and Steam 
("Producers") 


Limited Access 
of Air. 


"Cracking" 
of Oil Vapors. 


Bituminous substances: 








Oil-gas tar 
Water-gas tar 


Peat 


Peat tar 

Lignite tar 

Shale tar 

Gas-works coal ■ 

tar 
Coke-oven coal 

tar 

Wood tar 
Bone tar 


Peat tar 
Lignite tar 
Shale tar 

Producer-gas 
coal tar 




Lignite 






Pyrobituminous shales 








Blast-furnace 
coal tar 








Other Organic Materials: 

Wood 





















Petroleum products (e.g., " gas oils ") upon being subjected to a high 
temperature under more or less pressure in a closed retort will result in 
the formation of oil-gas tar; and when sprayed on incandescent anthracite 
coal or coke result in the production of water-gas tar (page 256). Peat, 
hgnite and pyrobituminous shales result in the formation of peat-, hgnite- 
and shale tars respectively, (1) when subjected to destructive distillation, 
or (2) upon undergoing partial combustion in an atmosphere of air and 
steam in a so-called *' gas. producer." Tars resulting from these two 
processes are similar in composition and hence are designated by the same 
name. Destructive distillation yields a larger percentage of tar than 
partial combustion in an atmosphere of air and steam. ' 

Bituminous coals form different kinds of tar depending upon the 
nature of the process. Thus gas-works coal tar and coke-oven coal tai' 
are produced by the destructive distillation of bituminous coal in gas- 



GENERAL METHODS OF PRODUCING TARS 167 

works retorts and coke-ovens respectively. Producer-gas coal tar is 
derived from the partial combustion of bituminous coal in an atmosphere 
of air and steam in a gas producer. Blast-mrnace coal tar results from 
the partial combustion of bituminous coal in a limited access of air in a 
so-called " blast furnace." 

Destructive distillation of wood results in the formation of wood tar, 
and of bones in the production of bone tar. 

In the order of their commercial importance, based on the quantities 
produced annually, tars may be grouped as follows, viz.: coke-oven 
coal-tar is produced in the largest quantity, gas-works coal tar comes 
next, water-gas tar, oil-gas tar and wood tar following in sequence. 
Insignificant quantities of producer-gas coal tar, bone tar, blast furnace 
coal tar, peat, lignite and shale tars are produced in the United States. 
Considerable shale-tar is produced in Scotland, also &m.aller quantities 
of blast-furnace coal tar. Lignite tar is produced in comparatively 
large quantities in Germany. The production of peat and bone tar 
has not assumed great importance anyw^here. 

We will now consider the various processes for producing tars in 
greater detail. 

DESTRUCTIVE DISTILLATION 

This process is used for destructively distilling infusible organic 
substances including non-asphaltic pyrobitumens, pyrobituminous shales, 
wood and bones. Tt consists in heating the substance to a high 
temperature in a still from which air is excluded, and the distillation 
is continued until the volatile constituents are driven off the residue 
carbonizes. The volatile constituents are grouped into two classes, 
viz.: non-condensable and condensable products, the former including 
the permanent gases, and the latter the aqueous liquor and tar. 

The nature of the ingredients formed during the distillation depends 
largely upon the nature of raw material used and the temperature at 
which it undergoes decomposition. As a rule, the older the substance 
from a geological stand-point, the higher the temperature at which it 
decomposes. At low temperatures, we find aliphatic (straight chain) 
hydrocarbons in the tar, also varying amounts of phenolic bodies, of 
toluene and naphthalene, but no benzene or anthracene. This is true 
in the case of peat, lignite, cannel coal and pyrobituminous shales. Where 
the destructive distillation takes place at a high temperature, aromatic 
hydrocarbons will predominate, including benzene and anthracene. 
This is true with bituminous coals. The aqueous hquor will show an 



168 



ASPHALTS AND ALLIED SUBSTANCES 



acid reaction in the case of wood and peat, and an alkaline reaction with 
lignite, coals and pyrobituminous shales. 

In general, the yield of tar depends upon five factors, viz.: the com- 
position of the substance, the temperature, the time of heating, the 
pressure, and upon the efficiency of the condensing system. These will 
be considered in greater detail. 

The Composition of the Substance, (a) The Percentage of Volatile Constitu- 
ents. The greater the percentage of volatile constituents, and conversely the smaller 
the percentage of ''fixed carbon," the larger the yield of tar. Figured on the basis 
of the dry weight of the non-mineral constituents, the yield of volatile matter 
will range as follows, commencing with the highest: wood, peat lignite, bituminous 
coal. The yields of tar follow in the same sequence, viz.: 

Wood 10 -20% 

Peat 71-15% 

Lignite 5 -10% 

Bituminous coal 3 - 7% 

(b) The Percentage of Oxygen in the Fuel. As a general rule, the greater the 
percentage of oxygen in the fuel, the greater the yield of tar. George Lunge ^ 
cites the following figures to show the relation between the percentages of oxygen, 
tar, and water, based on the dry weight of fuel: 



Fuel Contains 
Per Cent. 


Yield Tar, 
Per Cent. 


Yield Water, 
Per Cent. 


Oxvffen 5 — 6^ 


3 :o 

4.65 
5.08 
5.48 
5.59 


4.58 
5.86 
6.80 
8.60 
7.86 


Oxveen 6i- 7i 


Oxygen 7^- 9 


Oxygen 9 -11 

Oxygen 11 -13 



The Temperature, (a) The Temperature at which the Fuel Decomposer. As 
stated previously, each type of fuel has a definite temperature at which distilla- 
tion commences. The older the fuel from a geological standpoint, the higher this 
temperature, and hence the greater yield of coke, and the smaller that of tar. 
It would appear that a preliminary decomposition approaching a state of fusion 
occurs at this temperature which remains fairly constant until the carbonization 
is complete. The coke-forming property of bituminous coals depends upon the 
presence of constituents melting at a lower temperature than that at which car- 
bonization becomes appreciable. 

The kindling temperatures of the various fuels are: 

Dried wood 400° F. 

Dried peat 450° F. 

i Dried lignite 500° F. 

Bituminous coal 600° F. 

Anthracite coal 750° F. 

Coke 1000° F. 

>"Coal Tar and Ammonia," 5th Edition. New York. 1916. 



GENERAL METHODS OF PRODUCING TARS 169 

(b) The Temperature at which the Distillation is Performed. This is distinct 
from the preceding, and is determined by the quantity and intensity of the heat 
applied externally to the retort in which the destructive distillation takes place. 
It depends upon the nature of the heating medium, and the manner in which it 
is applied. The temperature may be close to that at which the fuel undergoes 
distillation, or it may be vastly in excess thereof. The higher the temperature 
above that necessary to cause incipient decomposition, the smaller the yield of 
tar, and the larger that of gas. This is strikingly illustrated by the following 
figures relating to the same coal distilled under different conditions: 

Low-temperature carbonization: Yield per ton: 16 gals, tar and 9000 cu. ft. gas. 
High-temperature carbonization: Yield per ton: 9 gals, tar and 11,000 cu. ft. gas. 

With a Derbyshire shale and a Notts cannel coal, the following yields of tar 
were obtained: 



Low temperature carbonization . . . 
Normal temperature carbonization. 
High temperature carbonization. . . 



Derbyshire Shale, 
Per Cent. 



Notts Cannel Coal, 
Per Cent. 



A Derbyshire coal which contained: carbon, 75.71 per cent; hydrogen, 6.27 
per cent; sulphur, 1.72 per cent; nitrogen, 1.72 per cent; oxygen, 11.59 per cent; 
and ash, 2.99 per cent; yielded the following per 100 kilograms: 

Carbonized at 800° C: Tar, 6.43 litres (specific gravity 1.00, containing 15 per 
cent of free carbon) and coke, 64.75 kilograms. 

Carbonized at 1100" C: Tar, 5.37 litres (specific gravity 1,207, containing 30 
per cent of free carbon) and coke 64.16 kilograms. 

It will be observed that a high temperature resulted in the formation of a 
larger percentage of free carbon in the tar, due to greater decomposition ("cracking") 
of the distillate. 

A certain bituminous coal, when carbonized at a low temperature (400-600° C.) 
produced unsaturated hydrocarbons, higher paraffines and oxygenated compounds. 
Between 600 and 800° C. methane and hydrogen were evolved, and at temper- 
atures above 800° C. the main product was hydrogen. In a laboratory test, it 
was found that on passing mixture of hydrogen and methane in equal volumes 
through heated coke at a temperature of 800° C, 2 per cent of the methane was 
decom])osed into hydrogen, and at 1100° C, 65 per cent was decomposed. 

Aromatic hydrocarbons, upon being subjected to a gradually increasing tem- 
perature (650°-800° C), are transformed as follows: 

Higher Benzene Homologues —> Lower Benzene Homologues—»Diphenyl— ^Naphthalene 
— >■ Anthracene. 

At temperatures above 800° C, the anthracene is decomposed into carbon and 
gas.i 

»/. Ind. Eng. Chem., 7, 1019, 1915; 8, 105, 1916; "The Pyrogenesis of Hydrocarbons," by 
A. E. Dunstan and F. B. Thole, /. Ind. Eng. Chem., 9, 888, 1917. 



170 ASPHALTS AND ALLIED SUBSTANCES 

The Time of Heating, (a) Thickness of the Fuel Layer. The deeper the layer 
of fuel in the retort or furnace, the greater the superheating, and consequently 
the smaller the yield of tar and the larger that of gas. When the layer is 
deep, the volatile portions are compelled to pass through a mass of incandescent 
fuel, so that the temperature of the gases is increased, due to the greater time of 
contact. This is the underlying principle in the manufacture of generator 
gas. 

It follows also that the greater the area of contact between the fuel and the 
heating surface, the shorter time it will take to raise the temperature of the former 
the requisite degree. Small charges of fuel may thus be heated more rapidly, which 
is conducive to the formation of a greater proportion of gas and tar and a smaller 
yield of coke. Slow heating, on the other hand, results in the production of a 
large proportion of coke, and smaller proportions of gas and tar respectively. It 
is for this reason that comparatively small and narrow retorts are used for the 
manufacture of illuminating gas, and very much larger chambers, where coal is 
treated to obtain coke. 

According to Ramsburg and Sperr,i the coking action progresses from the walls 
to the centre of the oven. The actual thickness of the coking zone is not much 
over \ in., but the drop in temperature across it is very great. It is esti- 
mated that in an, oven 18 in. wide, with a wall temperature of 1000° C, the 
average rate of advance is \ in. per hour. As this action progresses from all sides 
of the retort, it follows that the smaller its diameter, the shorter the time required to 
complete the process. 

{h) Size of the Fuel. The size of the lumps of fuel has an important bearing 
on the time of heating. If the lumps are too fine, they will pack together to such 
an extent that insufficient space is left between them for the transfer of heat by 
the gaseous products. On the other hand, if the lumps are too large, it will take 
an abnormally long time for the carbonization process to reach the centre of each 
lump, since the heat conduction of the fuel itself is poor. The proper size of the 
lumps is a question upon which almost every gas engineer has his own particular 
views. 

(c) Construction of the Retort or Furnace. The thickness of the walls, the method 
of heating, the size as well as the nature of the material of which the retort is 
constructed, all tend to influence the time of heating. Small units, the use of 
preheated gases for supporting the combustion, thin retort walls constructed of 
materials which have a relatively high conductivity at elevated temperatures, serve 
to decrease the time of heating. Fire clay was formerl}^ used for constructing the 
retort. Recently, however, silica has been adopted for the purpose on account of 
its superior strength and heat-conductivity at high temperatures. 

For manufacturing illuminating gas either horizontal, inclined, or vertical retorts 
have been used. In horizontal retorts, since it is impractical to fill the retort 
completely with fuel, considerable overheating of the volatile constituents will take 
place, due to their greater contact with the highly heated upper surface of the 
retort between the top of the fuel and the top part of the retort. In the in- 
clined and vertical varieties, this space is decreased and consequently there is 
less opportunity for overheating the products evolved during the distillation 
process. 

>/. Franklin Inst., 183, 319, 1917, 



GENERAL METHODS OF PRODUCING TARS 171 

The following figures show the influence of the retort's inclination on the yield: 





Vertical Retort, 
Per Cent. 


Inclined Retort, 
Per Cent. 


Horizontal Retort, 
Per Cent. 


Yield of tar 


6 

5 

50 


5i 
10 
55 


4 


Free carbon in the tar 


30 


Pitch obtained from the tar. . . . 


65 



Upon the Pressure. The greater the pressure, the longer the volatile prod- 
ucts are forced to remain in contact with the hot retort and incandescent fuel, 
and the greater, therefore, the carbonization. The use of reduced pressure hastens 
the removal of the volatile constituents and serves to increase the outputs of gas 
and tar, and to reduce the yield of coke. At the same time the period of dis- 
tillation is increased. In manufacturing illuminating or fuel gas, modern practice 
consists in carrying out the distillation under a moderate vacuum. On the other 
hand, when the main object is to produce coke, the pressure of the gas inside 
the retort is purposely allowed to increase somewhat. 

Upon the Efficiency of the Condensing System. As the vapors leave the 
retort, oven, blast-furnace, or producer at 500 to 800° C., all the constituents 
exist in the gaseous state, excepting the "free carbon" derived from the decom- 
position of the gases in contact with the highly heated walls, also particles of mineral 
matter carried over mechanically. The vapors are composed of a mixture of sub- 
stances, some congealing to solids, others condensing to liquids, and still others 
remaining as permanent gases at atmospheric temperature and pressure. As the 
vapors cool, the solids and liquids separate out, forming the tar. This separation 
is generally progressive, the higher boiling-point constituents condensing first, fol- 
lowed by substances of lower boiling-points, and finally liquids boiling slightly 
above atmospheric temperature. With this in view, the vapors may either be 
cooled slowly and the several fractions recovered separately by the Feld system 
(see p. 249), or they may be cooled rapidly, so that all condensible constituents 
are caught together in the form of ''tar," to be redistilled later into its components. 
It is a singular fact, that even when the vapors have been thoroughly cooled, the 
tar will not separate out completely, without further treatment. Part remains sus- 
pended in the gases as infinitesmally fine globules, known as a *'tar fog." This 
term is most expressive, since its behavior is very similar to that of an ordinary 
fog, alluding to the weather. Mere cooling will not condense a "tar fog," accord- 
ingly other means must be employed, as will be described later (p. 180). 

It is evident that the yield of tar depends largely upon the efficiency of the 
condensing system used in its recovery, of which the more important types will 
be considered in this chapter. 



172 ASPHALTS AND ALLIED SUBSTANCES 



PARTIAL COMBUSTION WITH AIR AND STEAM 

This takes place in manufacturing producer gas. Several forms of 
producers are in use, and peat (page 201), lignite (page 209), pyrobitu- 
minous shale (page 216) or bituminous coal (page 239) are variously 
employed as fuel. The reaction which ensues may be expressed as fol- 
lows, in which '' G " represents the carbonaceous matter present in the 
form of fuel: 

2C+0+H20 = 2CO+H2 

The resulting gas, known as " producer gas," is composed of carbon 
monoxide with a smaller proportion of hydrogen. When anthracite 
coal or coke is used as fuel, no tar results; with bituminous coal, tar is 
formed in certain types of producers but not in othere. (see page 240); 
and with peat or lignite, tar is produced in all types (see page 166), on 
account of the readiness with which they volatilize at low temperatures, 
and the comparatively large proportion of volatile constituents present. 
These tars correspond very closely in physical and chemical properties 
to the ones obtained from the corresponding processes of destructive 
distillation, but with the former the yield is smaller since most of the tarry 
matter is consumed. The following approximate percentages of tar are 
obtained in ordinary producers designed to produce the maximum yield 
of gas, viz. : 

Dry peat 1 -3% 

Dry lignite (pure) i-1% 

Bituminous coal 3 -5% 

Lignite carrying a moderate proportion of mineral matter (e.g. Messel 
lignite, p. 209) is treated in a special form of producer to obtain a small 
amount of gas and the largest possible yield of tar (4 to 14 per cant). 
This is brought about by introducing a limited and carefully regulated 
quantity of air and steam, sufficient only to support partial combustion. 
The same method is always followed in treating pyrobituminous shales, 
on account of the greater intrinsic value of the tar, of which 5 to 25 per 
cent is recovered. These processes approach destructive distillation 
very closely, the object being first to bring about incipient combustion 
of the lignite or shale and the non-condensable gases derived therefrom, 
thereby raising the temperature sufficiently to cause destructive distillation 
to ensue. It will thus become apparent that the yield of tar depends 
largely upon the quantities of steam and air introduced. 

When peat, bituminous coal or lignite containing a large proportion 
of mineral matter is treated in a producer, it is always intended to produce 
the largest possible yield of gas, and the smallest proportion of tar. 



GENERAL METHODS OF PRODUCING TARS 173 

PARTIAL COMBUSTION WITH A LIMITED ACCESS OF AIR 

This process takes place in manufacturing generator gas, also upon 
smelting ores in blast-furnaces. No tar is produced in manufacturing 
generator gas, hence this process ceases to be of interest from the bitu- 
minologist's standpoint. In the case of blast-furnaces, no tar results 
when anthracite coal or coke is used as fuel, but when bituminous coal 
is used, as is sometimes the practice in England and on the Continent 
(see page 238), 2 to SJ per cent of its weight of tar is produced. The air 
is forced into the blast-furnace from below, and travels upward through 
a comparatively thick layer of incandescent fuel. The oxygen on coming 
into contact with the fuel is first converted into carbon dioxide, which on 
rising through the incandescent layer combines with more carbon, forming 
carbon monoxide. The heat generated volatilizes a certain amount of 
the bituminous coal in the upper layers from which the tarry matters 
escape unconsumed. 

CRACKING OF OIL VAPORS 

In manufacturing oil-gas, crude petroleum or a heavy distillate 
known as " gas-oil " is sprayed under more or less pressure into a 
closed retort heated to redness. This causes the oil to decompose 
into a permanent gas and from 5 to 10 per cent by weight of oil-gas 
tar (see page 260). The reaction, known as '' cracking," results in 
the breaking down of the hydrocarbons present in the petroleum or 
gas oil into simpler substances. 

Water-gas is produced by the combustion of anthracite coal or coke 
in an atmosphere of steam (page 256) according to the following 
reaction : 

C+H20 = CO-fH2. 

The gas consists theoretically of equal volumes of carbon monoxide 
and hydrogen. It burns with a non-luminous flame, and when intended 
for illuminating purposes must be enriched or " carburetted.'' The 
highly heated water-gas as it is generated, is accordingly mixed with a 
spray of crude petroleum or gas oil, then passed into a carburettor in 
which the oil becomes vaporized, and finally through a superheater main- 
tained at a temperature sufficiently high to crack the oil vapors into 
permanent gases. From 2 to 10 per cent of tar is produced, based on 
the weight of the petroleum or gas-oil used. This tar is known as water- 
gas tar and is similar in its physical and chemical properties to oil- 
gas-tar (see page 262). 



174 



ASPHALTS AND ALLIED SUBSTANCES 



METHODS OF SEPARATING TARS 

The vapors resulting from the foregoing pyrogenic processes are 
treated to remove the tar and aqueous hquor by one or more of the follow- 
ing devices: 

(1) Condensers Mere coohng 

(2) Static Scrubbers 

(3) Mechanical Scrubbers. . . 

(4) Deflectors 

(5) Filters 

(6) Electrical Precipitators. . . In contact with an electrical discharge 



In contact with liquids 
In contact with solids 



Each type will now be described separately : 

(1) Condensers. The function of a condenser is to cool the hot 
vapors by circulation in a closed system of pipes surrounded by air or 
water. The following represent the most important types: 

Hydraulic Main. This consists of a vertical metal pipe of liberal cross-section, 
cooled by the surrounding air. It is used in the manufacture of coal gas, oil 

gas and coke (see pp. 230, 260). The vapors as 
they leave the retort are passed upward through 
the hydraulic main illustrated in Fig, 58, the top 
of which bends downward and dips into a closed 
trough partly filled with water, which acts as a 
seal and washes the vapors as they bubble through. 
This enables any retort being recharged or repaired, 
and at the same time prevents the vapors gener- 
ated by the other retorts from escaping into the 
atmosphere. Most of the ammonia is dissolved 
in the water contained in the trough, and a large 
proportion of the tar condenses out. 

Air-condensers. These are illustrated in Fig. 
59. The gases are circulated through vertical 
pipes alternately connected at the top, and lead- 
ing into a closed chamber below separated 
by partitions through which water is slowly 
allowed to circulate, which catches the tar and 
ammonia. 

Water-condensers. In these the vapors are passed through a series of pipes 
around which water is allowed to circulate, as illustrated in Fig. 60. The cooling 
water from one compartment is passed through the next, in such a manner that 
the vapors and water travel in opposite directions. The ammoniacal liquor and 
the tar separate out at the bottom. In manufacturing coal gas, the vapors after 
they leave the hydraulic main, are passed through a device of this description, 
which serves to cool them to atmospheric temperature, and results in a more 
complete sej)aration of tar, than is possible in the former. 




Fig. 58. — Hydraulic Main, 



GENERAL METHODS OF PRODUCING TARS 



175 



(2) Static Scrubbers. Static scrubbers are stationary contrivances 
through which water is caused to circulate. They are classified into: 
rain, hurdle and baffle scrubbers. 

Rain Scrubbers. Consist of closed chambers into which the gas is introduced 
at the bottom and washed with jets of water impinging against screens which serve 
to break them into a fine spray, illustrated in Fig. 61. This represents the simplest 
form of static scrubber and has been superseded by more efficient types, due to 
the very short time of contact between the vapors and the water. They are 
excessively large and expensive to operate, and there are apt to be "dead corners" 
as the gases rush through. 

Hurdle Scrubbers. These are built in the form of a tower whose height is 
usually four times its diameter, and separated into compartments by perforated 



Vapor. 



<-^ /i^^ /^^, /^^ C^-^ 




Tar ' 




Vapor 



Fig. 59. — Air Condenser. 



Fig. 60.--Water Condenser. 



shelves carrying coke (Fig. 62), or in the case of the Zschocke scrubber, wooden 
slats stacked in alternate directions forming a checker work (Fig. 63). The func- 
tion of the coke or wooden slats is to break up the jets of water introduced at 
the top and secure intimate contact with the vapors which pass in at the bottom 
and out at the top of the scrubber. The coke scrubber is open to the objection 
that the interstices of the coke become clogged with tar, and thus soon loses its 
efficiency. 

Baffie Scrubbers. These are constructed so the water is caused to flow from 
baffle to baffle in a zigzag direction, whereas the vapors pass upwards, as shown 
m Fig. 64. This brings the vapors into contact with a large surface of moving 
water, and at the same time prevents the formation of dead pockets as is the 
case with some of the foregoing types. 



176 



ASPHALTS AND ALLIED SUBSTANCES 



Vapor Exit 



.Screens 




w/mm/mm/m/mmm///m///m/m. 

Fig. 61.— Rain Scrubber. 



Wafer- 



Nine Rows of 

' Wooden Slats 

alternately af 

Pight Angles 




Fig. 63.— Hurdle Scrubber Filled with 
Wooden Slats. 



a i^^Ca 




; '-Coke 



Fig. 62.— Hurdle Scrubber Filled with 
Coke. 



\ Vapdr 



Wafer 



Vapor 




Fig. 64.— Baffle Scrubber. 



GENERAL METHODS OF PRODUCING TARS 



177 



(3) Mechanical Scrubbers. In this type part of the mechanism 
is caused to revolve, and thus thoroughly comingle the water with the 
vapors. They include the following: 

Feld Centrifugal Scrubber. The "Feld Centrifugal Scrubber" as illustrated in 
Fig. 65, is composed of a number of superimposed chambers, each provided with a 
plurality of gas ports (a), and a series of inverted hollow, frustums of cones (6) 
mounted on a central vertical shaft, the outer cone having its top covered. The 
washing liquor enters at the top and overflows from chamber to chamber, part 
being drawn off from each chamber. The lower edges of the cones dip into the 
hquid, and being revolved at a high speed, carry it up along the inner surfaces, 
to be hurled off tangentially in a fine spray through perforations near the top 
of the outer cone. A perforated plate (c) mounted on the shaft in the dome, 
serves to separate any liquid entrained with the vapors leaving the washer. This 



OasExit 




Vapor 



Vapor 




Fig. 65. — Feld Centrifugal Scrubber 



Fig. 66. — Reading Centrifugal 
Scrubber. 



type is very efficient and economical, and forms the basis of the Feld system for 
fractioning coal tar. (See p. 249.) 

Reading Centrifugal Scrubber. The Reading centrifugal scrul^ber, illustrated in 
Fig. 66, consists of two connecting compartments {A and B) separated by a disc 
(C). Each compartment carries a set of rapidly revolving blades mounted on a 
horizontal shaft. Water is introduced through the casing at the bottom and churned 
into a spray. The vapors are thrown against the casing wall by centrifugal force, 
and any particles of tar or dust retained by the liquid. After the vapors are 
treated in chamber (A) they flow through an opening near the centre of the disc 
into chamber (B), where they are treated in a similar manner, whereupon the 
cleansed vapors are drawn off through an aperture surrounding the shaft. 

Thiesen Centrifugal Scrubber. This consists of a rapidly revolving cylindrical 
drum, carrying on its periphery an oblique spiral vane, almost touching the sur- 



178 



ASPHALTS AND ALLIED SUBSTANCES 



rounding casing lined with wire netting, which serves to retain water in its meshes 
by capillarity. This washer is illustrated in Fig. 67. The vapors enter at (a) 
and are drawn through the spiral channel (6) where they commingle with water 
sprayed through the tangential openings (c). The vapors pass out through the 
pipe (d), and the cleaning liquid at (e). The vapors are rapidly and thoroughly 
washed with comparatively little expenditure of power. 

Schwarz-Bayer Disintegrator. This is composed of a series of blades or vanes 
fastened concentrically to a cylindrical frame-work and revolving alternately in 
opposite directions (Fig. 68). The washing water, entering at (A), is broken up 
into a fine mist by the rapidly revolving vanes, and finally passes out at (B). 
The vapors are introduced at the circumference (C), being drawn off at the centre 
of the casing through (DD). 

(4) Deflectors. No water is employed in thip type of apparatus, 
which is generally used to supplement the scrubbers, and remove the 



^axo<-c 




Fig. 67. — Thiesen Centrifugal Scrubber. 



last traces of tar from the vapors. They operate on the principle that when 
a rapidly moving stream of vapor impinges against an obstruction, which 
changes the direction of flow, the suspended tar is caused to condense. 

P. & A. Tar Extractor. This constitutes one of the best known deflectors. It 
is popularly called the "P. & A. Type," after the inventors, Messrs. Pelouze 
and Audouin, and is illustrated in Fig. 69. The vapors are caused to flow through 
narrow apertures in a series of perforated metal cylinders mounted concentrically 
so that the apertures in one cylinder fall opposite the solid portions of the adja- 
cent cylinders. The vapors are thus caused to assume a zig-zag travel, and their 
direction changed many times. This causes the tar to precipitate out, and collect 
at the bottom of the extractor, where it is drawn off. By the chain and weights, 
the cylinders rise or fall in the liquid, exposing a greater or lesser surface as the 
volume of vapors increases or decreases. 

Centrifugal Deflector. This is illustrated in Fig. 70, and consists of two com- 
partments (1) and (2), connected by the orifice (3). The vapors enter at (4) 
and their velocity forces them tangentially against the inner surface of compart- 
ment (1), imparting a whirling motion to the current. When the vapors enter 



GENERAL METHODS OF PRODUCING TARS 
C 



179 




Fig. 68. — Schwarz-Bayer Disintegrator. 




Fig. 70. — Centrifugal Deflector. 




Fig. 69.— p. & A. Tar Extractor. 




vm//fWfm/w////////////////////mf}////v////////7 



Fig. 71.— Smith Tar Extractor. 



180 



ASPHALTS AND ALLIED SUBSTANCES 



• Vapors 



compartment (2) they are caused to whirl in the opposite direction and leave 
at (5). The rapid change in motion coupled with centrifugal force causes the tar 
to separate and flow into the sumps (7) and (8). 

(5) Filters, ^miih Tar Extractor. This represents the most successful 
type of filter, and is illustrated in Fig. 71. The pump (B) forces the vapors 
through a porous diaphragm (E), about i in. thick composed of spun 
glass-wool, supported betv/een two metal screens. No tar is retained in 
the diaphragm, but in passing through, the fog coalesces into larger 

globules which on account of their 
, iTT.rlTl|[Tf[jflJ|t. . greater size and weight can no longer be 

carried forward by the gas current, and 
accordingly settle out into a sump (G), 
whence it is drawn off from time to 
time. This extractor operates to best 
advantage on tars containing little to 
no free carbon. The temperature should 
be sufficient to maintain the tar in a 
liquid condition, and the pressure main- 
•-T" ~ 1 tained at 2| to 4 lbs. Since no water 

is employed, the separated tar contains 
less than 1 per cent, which is a decided 
advantage, and in addition practically 
every vestige of tar is removed from 
the vapors. 

(6) Electrical Precipitators. Cottrell 
System, This consists in subjecting the 
vapors to a '' silent " or " glow " uni- 
directional electrical discharge of from 
15,000 to 50,000 volts, in the type of apparatus illustrated in Fig. 72. 
This method has^ also been described by Steers and others.^ The elec- 
trical current effectively breaks up tar fogs, but up to the present time 
the method has only been used in a limited way. 



Vapors 




Hoppers for Discharge 

Fig. 72.— Cottrell Electrical 
Precipitator. 



METHODS OF DEHYDRATING TARS 

The tar separated from most of the foregoing processes carries more 
or less water, derived from the hquor normally associated with the tar 
vapors, as well as any water introduced in the condensers, static and 
mechanical scrubbers, for cooling or cleansing purposes. When a large 



»J. Soc. Chem. Ind., S3, 1145, 1914. 



GENERAL METHODS OF PRODUCING TARS 



181 



amount of extraneous water is mixed with the tar, most of it is first allowed 
to settle out by gravity described in methods (1) and (2) below. 
The following devices are used for dehydrating tars: 

(1) Settling Tanks. The oldest method consists in storing the tar 
in large metal or masonry tanks for the double purpose of keeping a 
sufficient supply of tar on hand to enable the works to operate continu- 
ously, and also to allow as much as possible of the entrained aqueous 
liquor to separate out. The liquor being of a lower density than the tar, 
rises to the surface, whence it is drawn off through a series of small outlet 
cocks on the side. If the tar is sufficiently fluid, a prolonged standing 
will allow much of the aqueous Hquid to separate at ordinary temperatures. 
On the other hand if the tar is viscous, the process can be facilitated 
by maintaining the tar at a moderate temperature by means of steam 
coils at the bottom of the tank. The latter are of special importance 
in winter time, when the tar is very apt to decrease in fluidity. Gas- 
works tars treated in this manner still carry between 4 and 10 per cent 
of water, coke-oven tars between 3 and 6 per cent and water-gas tars 
up to 40 per cent. 

(2) Baffle-plate Separator. This apparatus is used for the continuous 
separation of tar from the large quantity of washing water introduced 
in the condensers, static and 

mechanical scrubbers [methods Tar and water 

(2) and (3), (pp. 175, 77).] The 

separator is illustrated diagram- 

matically in Fig. 73. The baffle 

plates {A) run from the top down 

to within a foot of the bottom 

and alternating with these are 

dams {B) extending from within 

4 in. of the bottom to within 4 

in. of the water line. The path 

of the water and tar is under 

the baffle plates and over the dams, thus giving the latter an opportunity 

to settle out, and incidentally form a seal for the dams. The speed of flow 

is regulated so that the effluent is practically clear water, the tar being 

drawn off automatically through a syphon when it reaches the proper level. 

(3) Heating Quietly under Pressure. Refractory tars can very 
often be dehydrated by heating under pressure in a closed boiler. As 
the temperature rises, the fluidity of the tar increases, enabling it to 
settle out more or less readily. The process is intermittent, and is not 
universally appHcable. 




Fig. 73.— Baffle-Plate Tar Separator. 



182 



ASPHALTS AND ALLIED SUBSTANCES 



(4) Wilton Process. This is a continuous process in which the tar 
is heated to 170 to 180° C. at a pressure of about 30 lbs. per square inch. 
The temperature of the tar is regulated by the speed with which it is 
pumped through a coil in a furnace heated by coke. It is then released 
into a vapor-chamber at atmospheric pressure, whereupon the water 
and the light oils speedily evaporate, since they are maintained at a 
temperature considerably higher than their boiling-points. This is 
accompanied by copious frothing in consequence of the fact that each 
volume of water at its boiling-point (100° C.) becomes converted into 
1640 volumes of steam. The resulting vapors are condensed to recover 
the light oils. The dehydrated tar is passed through an economizer 
which utilizes the heat in preheating the crude tar.^ 

(5) Heating a Thin Stream under Vacuum. This is also a con- 
tinuous process and one of the most successful ones for dehydrating tars. 
The crude tar is allowed to flow to a thin stream over steam coils or heated 
baffle-plates in a closed vessel maintained under a moderate vacuum. 
The tar is allowed to run into the vessel, and then removed by a pump 
which at the same time maintains the vacuum. The vapors are con- 
densed to recover the light oil. An apparatus of this kind will treat about 
50,000 gallons of tar in 24 hours reducing the water to less than 0.5 per 
cent. 2 

(6) Centrifugal Method. This method is also continuous, and has 
been used with more or less success abroad. The tar is first heated to a 

temperature of 40 to 50° C. and run 
into the rapidly revolving drum of a 
centrifugal separater, illustrated in 
Fig. 74. The tar being heavier than 
the water is forced to the periphery, 
the water forming a cylindrical layer 
inside. An annular diaphragm (A) 
attached to the upper part of the 
centrifugal has a ring of perforations 
where it comes in contact with the 
drum at (B). The crude tar is intro- 
FiG. 74. — Centrifugal Tar Dehydrator. duced through the pipe (C) below the 

diaphragm. The speed with which 
the drum revolves causes the tar to flow through the perforations into 
the upper portion of the centrifugal, where it is removed through the 

iC. H. Webb, Eng. News, 68, 109, 1912; J. Gas Lighting, 124, 505, 1913; Gas World, 59, 
626, 1913; E. V. Chambers, Am. Gas Light J., 103, 389, 1916; A. E. Mottram, Gas J., 137, 
464, 1917. 

2R. P. Perry, 8th Intern. Cong. Applied Chem., 10, 242, 1912. 



nqu^ous Liquor E 




GENERAL METHODS OF PRODUCING TARS 183 

pipe (D). The water is drawn off through (E) below the diaphragm, 
which bars its passage into the upper section. This method is 
particularly suited for treating tars having approximately the same 
specific gravity as water, as for example water-gas tar. The centrifugal 
is revolved at a speed between 2000 and 3000 revolutions per minute. 
Tars "containing between 30 and 90 per cent of water will have the 
percentage reduced to less than 1 per cent in one treatment. A large 
portion of the free carbon contained in the tars is also removed, and 
affixes itself to the inner walls of the drum from which it must be scraped 
occasionally.^ 

(7) Electrical Method. This method has only been worked out ex- 
perimentally, and consists in passing the tar between electrodes charged 
with a high potential current. This causes the particles of water to 
coalesce, so that they will separate out readily on subjecting the tar to a 
temperature of 80° C.^ 

(8) Feld System of Fractional Cooling. This process also results in 
the production of dehydrated products. The method will be described 
in detail on page 249. 

;Am. Gas Light J., 102, 349, 1915. 

2U. S. Pats. 1,116,299, Nov. 3, 1914; 1,142,759, 1,142,760, and 1,142,761 of June 8, 1915, 
all to R. E; Laird and J. H. Raney. 



CHAPTER XIV 
WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH 

WOOD TAR AND WOOD-TAR PITCH 

This chapter will deal with the treatment of wood, either by destruc- 
tive distillation, or by a combination of steam and destructive distillation .^ 
The treatment of resinous woods by the steam distillation process alone, 
for the recovery of turpentine and other oils, does not fall within the 
scope of the present treatise. 

Varities of Wood Used. From the standpoint of destructive distilla- 
tion, woods may be divided into two classes, viz. : 

Hard Woods, including the maple, birch, beech, oak, poplar, elm, 
willow, aspen, alder, ash, hickory, chestnut and eucalyptus. 

Resinous or Soft Woods, including the pine, fir, cedar, cypress, spruce, 
hemlock, larch or tamarack. 

The trees from which hard woods are obtained are known as " broad- 
leaved " or '' deciduous trees," and those producing resinous- or soft- 
woods are termed " coniferous trees " or '' evergreens." Soft woods 
are distinguished from hard woods principally in that the former contain 
larger quantities of turpentine and resin. The distillation of hard wood 
aims at the recovery of wood alcohol, acetates, tar and charcoal, whereas 
the distillation of resinous wood (soft wood) is directed to the recovery of 
turpentine, wood oils, tar and charcoal. 

In the wood-distilling industry the basis of measurement is a cord, 
which is taken to equal 90 cu. ft. of the closely stacked wood containing 
15 per cent of moisture. The weight of a cord varies with different kinds 
of wood, from about 1700 lbs. in the case of white pine and poplar, to 
about 4000 lbs. in the case of oak. 

1 "Chemical Methods of Utilizing Wood," by F. P. Veitch, Circular 36, U. S. Dept. Agr., 
Bureau of Chem., Wash., D. C, Aug. 29, 1907; "Wood Used for Distillation in 1906," Forest 
Service Circular No. 121, U. S. Dept. Agr., Wash., D. C, Dec. 6, 1907; "Wood Distillation," 
by W. C. Geer, Forest Service Circular No. 14, U. S. Dept. Agr., Wash., D. C, Nov. 5, 1907; 
"Wood Turpentine, Its Production, Refining, Properties and Uses," Circular No. 144, U. S. Dept. 
Agr., Bureau of Chemistiy., Wash., D. C, 1912; "Yields from the Destructive Distillation of 
Certain Hardwoods," by Hawley and Palmer, Bull. No. 129, U. S. Dept. Agr., Wash., D. C, 
Sept. 10, 1914; "Yields from the Destructive Distillation of Certain Hardwoods," by R. C. Palmer, 
Bull. No. 508, U. S. Dept. Agr., Wash., D. C, March 6, 1917; "The Distillation of Wood," by J. 
C. Lawrence, J. Soc. Chem. Ind., 5T., 37, 1918; "The Influence of Moisture on the Yield of Products 
in the Destructive Distillation of Hardwood," by R. C. Palmer and H. Cloukey, J. Ind. Chem., 10, 
262, 1918. 

184 



WOOD TAR, WOOD-TAR PITCH AND ROSIX PITCH 



185 



For purposes of destructive distillation, the wood should be as dry- 
as possible, as during the process all the moisture must be evaporated 
before the wood decomposes. The smaller the percentage of moisture 
contained in the wood, the more rapid the distillation process and the 
smaller the quantity of fuel required. It is advisable therefore, to cut 
and stack the green wood containing 20 to 50 per cent of moisture from 
6 months to 2 years, during which the moisture content will fall to between 
12 and 25 per cent. 

Yields of Distillation. The following figures will give a general idea 
of the average yields upon distilling a cord of the respective classes of 
wood. 





Hard Woods. 


Soft (Resinous) Woods. 


Turpentine 

Wood oils 






8- 12 Gals. 

8- 20 Gals. 

40- 52 Bu. 

150-350 I bs. 


5-25 Gals.* 
30-75 Gals 


Crude alcohol (containing acetone) 

Tar 

Charcoal 


2- 4 Gals. 
30-60 Gals. 
25 -40 Bu 


Acetate of lime 


50-100 Lbs 







* Saw-dust yields 5 to 10 gals, of turpentine and light wood 10 to 25 gals, per cord. 

Hard- Wood Distillation. The following figures show the yields of tar 
and charcoal from the various hard woods in percentage, based on the 
dry weight of the material .^ 





Tar, 
Per Cent. 


Charcoal, 
Per Cent. 


Hickory 


13.0 

12.8 

12.0 

9.4 

7.8 
4.6 


37.7 
40.6 
40.6 
41.9 
45.7 
47.6 


Maple 


Birch 


Beech 


Oak 


Chestnut 



In the United States, the principal centres for hard wood distillation 
are in the States of Pennsylvania, New York and IMichigan. Soft wood 
distillation is carried on largely in the States of Florida, Georgia, North 
and South Carolina and Alabama. 

The crude products of the distillation of hard wood may be grouped 
into four classes, viz.: 

(1) Non-condensable gasea 20-30% 

(2) Aqueous distillate (crude pyroligneous acid) 30-50% 

(3) Turpentine, wood oils, and wood tar 5-20% 

(4) Charcoal 20-45% 

»See also Table 5, p. 7, Bull. 508, U. S. Dept. Agriculture, Wash., D. C, March 6, 1917, 



186 



ASPHALTS AND ALLIED SUBSTANCES 




When hard wood is heated in a retort, water passes off below 150° C. 
after which decomposition sets in. With soft (resinous) wood, tur- 
pentine and water commence to distil between 90 and 100° C. and con- 
tinue to 150° C, whereupon products of destructive distillation pass over. 
The distillation process is practically complete at 430° C. In the case of 
hard wood, the first series of products which pass over (between 150 to 
280° C.) include acetic acid, methyl alcohol and wood creosote; the 
second series (280 to 350° C.) consist of non-condensable gases (about 
53 per cent of carbon dioxide, 38 per cent of carbon monoxide, 6 per cent 

of methane, 3 per cent of nitrogen, 
etc.); the third series (350 to 
400° C.) are composed of soUd 
hydrocarbons and their deriva- 
tives. The yields of methyl alco- 
hol and acetic acid increase with a 
rise of temperature up to 300° C. 
beyond which they decrease, and 
moreover the recovery is greater 
when the wood is heated slowly, 
than when the distillation is forced. 
In distilling hard woods large 
rectangular iron retorts are used, 
measuring 6 ft. in width, 7 ft. 
high and either 27 or 50 ft. long, depending upon whether they are 
intended to hold 2 or 4 carloads. The retorts are set in brick work, 
and provided with large air-tight iron doors at the ends. The wood is 
loaded on small iron cars holding between 1 and 3 cords each (Fig. 75) 
which are run on tracks directly into the retorts. 

The arrangement of a modern wood-distilling plant is shown in Fig. 
76; where A represents a car; B, the retort; C, first cooler; D, 
second cooler; E, the acetate drying floor; a, condensers; b, liquor 
trough; c, gas main to boilers; i, fuel conveyor; m, fire-place; n, ash 
pit; 0, hinged spout to deliver fuel from i to m. After the retort 
is charged, the doors are closed and heat applied slowly, either by 
burning the non-condensable gases resulting from the distillation 
process, or by atomizing the tar underneath the retort with a jet of 
steam. Unless the gases are stored in a gas-holder, the process is 
is started by burning a small amount of wood on an auxiliary grate 
beneath the retort. 

The vapors from the retort is passed through condensers, where the 
pyroUgneous acid, alcohol and other condensable constituents are recov- 



FiG. 75. — Iron Cars Used in the Distillation 
of Hardwood. 



WOOD TAR, WOOD-l^AR PITCH AND ROSIN PITCH 



187 



ered. These are conveyed to large settling tanks, and allowed to rest 
quietly until the tar settles out. 

The distillation process continues from 20 to 30 hours, whereupon 
the fires are extinguished and the retort allowed to cool. The small 




wmTTm// 



)^/Mi)j^/jf^hm)mi}^^ 



r 



1ST COOLER 



2vo COOLEfl 



Fig. 76. — Modern Wood Distilling Plant. 




Fig. 77.— Plant for Refining Wood Tar. 



iron cars now carrying charcoal are quickly run from the retort into 
large iron coolers, similar in size and shape to the retort itself, and the 
doors are closed to prevent access of air. 

The general arrangement of a refining plant is shown in Fig. 77, 
where A 1-2 represents the raw liquor vats, B 1-6 represent the raw 
hquor settling tanks, C 1 the tar still, C 2-3 the raw liquor still, D 1-2 



188 



ASPHALTS AND ALLIED SUBSTANCES 



the neutralizing vat, E 1-3 the lime-lee stills, F 1-3 the alcohol stills, G 
the weak alcohol storage tank and H the strong alcohol storage tank. 
Table XVI shows a diagrammatic outline of the products obtained upon 
distilling hard wood, and refining its distillates. 



Non condensable Gases 
(Burned under retort) 



TABLE XVI 

Hakd Wood 
Distilled Destructively 



i 

Condensable Distillate 

Separated by settling into: 



Crude Aqueous portion 
Separated by distillation into 

I 



Charcoal Residue 



Distillate, known as 
" Pyroligneous acid" 



Tarry Residue 
g_y 



Neutralized with lime and distilled 



Raw Tar 

Distilled into: 

I 

i i 
Distillate of Residue of 
—^Acetic Acid Boiled Tar 
^Redistilled 



i 



i 



Distillate composed of Residue composed of crude 
crude dilute wood acetate of lime. Converted 
by roasting into gray acetate 
of lime. Then treated by 
one of the following methods 



i 
Light oil 



alcohol containing 
acetone. Rectified 
into: 
I 



1 1 © 

Acetone Wood alcohol Distilled with 
Sulphuric acid 
I 



1 i 

Distillate of Residue of 
Acetone Calcium 

Sulphate 



Converted into 
Other acetates 

I 

i i 

Other Acetone 
Acetates 



i 
Heavy oil 



Residue of 
Wood-tar pitch 



Distilled at a high 
temperature alone 



i 
Light 
Acetone 
Oila 



i i 

Heavy Residue of 

Acetone Calcium 

Oils Carbonate 



After the pyroligneous acid and tar have been separated by settling, 
the crude products are distilled independently to recover any pyroligne- 
ous acid from the crude tar, and conversely, any tar retained by the 
crude pyroligneous acid (dissolved in the alcohol and acetone present). 
The dehydrated tar, known as " boiled tar " or '' retort tar," amounting 
to between 3 and 10 per cent of the weight of the wood, may be utilized 
in one of the following ways: 

(1) It may be sold as such, and used for preserving wood. 

(2) It may be burned under the retorts as fuel. 

(3) It may be subjected to fractional distillation to recover the 
Hght oils boiling below 150° C, heavy oils boiling between 150 and 240° 
C, and the residual pitch constituting between 50 and 65 per cent by 



WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH 



189 



weight of the tar. The hght oils are used as solvents in manufacturing 
varnish, and the heavy oils after further refining are marketed as commer- 
cial wood creosote which finds a sphere of usefulness as a disinfectant, 
preservative, and flotation oil (p. 455). 

The combined liquors containing acetic acid, methyl alcohol, and acetone are 
neutralized with lime, and re-distilled in the "lime-lee still." In this manner, 
the alcohol, acetone and ketones pass over, whereas the acetic acid remains in 
the still combined with the lime (calcium acetate) and contaminated with a small 
proportion of tarry matter. The residue containing from 65 to 75 per cent of 
pure acetate of lime is known commercially as "brown acetate of lime." The 
distillate is fractioned in a column still to separate the pure wood alcohol and 
acetone from the water and other impurities present (ketones, etc.). 

Brown acetate of lime is first roasted at 230° C. to decompose any tarry matters. 
It may then be distilled with sulphuric acid to produce commercial acetic acid, 
which is recovered as distillate; or it may be converted into aluminium, chromium, 
copper, lead or sodium acetate; or it may otherwise be distilled alone in an iron 
retort, whereupon acetone is first obtained, and followed at 400° C. by the "ace- 
tone oils" (light acetone oil boils between 75 and 130° C, and heavy acetone 
oU between 130 and 250° C). 



Soft (Resinous) Wood Distillation 

wood) a different method is 
followed. Iron or steel retorts 
varying in capacity from one to 
four cords are used, constructed 
either vertically or horizontally, 
as sho\vn in Fig. 78. Low-pressure 
superheated steam, or saturated 
steam under high pressure is in- 
troduced into the retort to re- 
move the turpentine, and then the 
volatile oils (known as '' heavy 
oils "), leaving a residue of coke 
behind 



In treating soft wood (resinous 




Fig. 78.— Retorts for Distilling Soft Wood. 
Three classes of resinous wood are used for the purpose: 



(1) " Light wood " containing comparatively large quantities of 
turpentine. 

(2) " Stumps " which also contain more or less turpentine. 

(3) Saw-mill waste which is rather poor in turpentine. 

The wood is first '' hogged," or in other words cut into chips before 
it is introduced into the retort. The temperature is raised gradually 
to 200° C. as the steam passes through the retort. Water and crude 
turpentine distil over first and are separated by settling. As the tempera- 



190 ASPHALTS AND ALLIED SUBSTANCES 

ture rises above 200 to 220° C. the wood commences to decompose into 
tarry substances, and at about 250° C. the resins present break up into 
'* rosin spirits " and '' rosin oils." Both the crude turpentine and the 
heavy oils are redistilled separately, the former producing purified wood 
turpentine and the latter pine oil, rosin oil and pitch. Rosin spirits 
boils between 80 and 200° C, pine oil between 190 and 240° C, and 
rosin oil between 225 and 400° C. 

In some cases the Hght wood is subjected to a process of destructive 
distillation without using steam. The temperature is raised slowly and 
the distillate under 200° C. caught separately to avoid contamination 
with tarry matters. After the temperature rises above 200° C, the 
process follows the same course as for hard- wood distillation. The 
distillate under 200° C. is fractioned into light and heavy oils respectively. 
The light oil is in turn redistilled to recover the rosin spirits, wood tur- 
pentine and a part of the pine oil. The heavy oil is similarly redistilled 
to separate the pine oil, rosin oil and a part of the pitch. The crude 
tar obtained above 200° C. is distilled to recover any acetic acid, and 
the residue either marketed as ^^ pine tar " or distilled to separate the light 
and heavy oils from the pine-tar pitch obtained as residue. This process 
is illustrated diagrammatically in Table XVII. 

TABLE XVII 

Light Wood (Pine or Resinous Woods) 
Steam distilled up to 200° C, and then distilled destructively 

. \ 

i i i 

Water Below 200° C. Above 200° C. 

Condensable Distillate. Redistilled into: Destructive distillation occurs 

I ! 



4* ^l* 4' v 4' 

Light oils Heavy oils Non-condensable Condensable Charcoal 

(Fractioned) (Fractioned) gases Distillate Residue 



I 1 1 1 i 1 Treated the same as in 

Rosin Wood Part oi Balance of Rosin Pine-tar Hard wood distillation 

Spiritf Turpentine Pine oil Pine oil oils pitch (See Table XVI) 

Pine tar is also marketed under the name " Stockholm tar," and 
contains a certain proportion of rosin. 

Wood Tars. The bituminous products derived from the destructive 
distillation of wood are designated commercially as hard- wood tar, 
pine tar, hard-wood-tar pitch and pine-tar pitch. 

The physical and chemical characteristics of the tars and correspond- 
ing pitches vary, depending upon the kind of wood used, as well as the 
exact method of treatment. The following figures will give a general 



WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH 



191 



idea of the characteristics of the dehydrated hard-wood tar and pine tar 
ordinarily encountered in the American market: 



(Test 1) 


(Test 7) 


(Test 8) 


(Test 9) 


(Test 13) 


(Test 15) 


(Test 16) 


(Test 17a) 


(Test 19) 


(Test 21a) 


(Test 216) 


(Test 21c) 


(Test 22) 


(Test 23) 


(Test 24) 


(Test 28) 


(Test 30) 


(Test 32) 


(Test 33) 


(Test 35) 


(Test 37) 


(Test 37a) 


(Test 41) 


(Test 42) 


(Test 43) 



Hard-wood Tar 

Color in mass Black 

Specific gravity at 77° F 1 . 10-1 . 20 

Viscosity Fairly liquid 

Consistency at 77° F Liquid 

Odor on heating Characteristic 

Fusing-point Below 20° F. 

Volatile matter at 500° F., 4 hrs 35-60% 

Flash-point 50-75° F. 

Fixed carbon 5-20% 

Solubility in carbon disulphide 95- 100% 

Non-mineral matter insoluble 0-5% 

Mineial matter 0-1% 

Carbenes 0-2% 

Solubility in 88° naphtha 50-90% 

Solubility in absolute alcohol Almost complete 

Solubility in glacial acetic acid Almost complete 

Solubility in acetic anhydride Almost complete 

Sulphur 0.0% 

Oxygen 2-10% 

Naphthalene None 

ParafiBne None 

Sulphonation residue Trace to 5% 

Saponifiable constituents 5-25% 

Resin acids Up to 15% 

Diazo reaction Yes 

Anthraquinone reaction No 

Liebermann-Storch reaction Yes 



Pine tar {from 
Resinous Woods) 
Brownish 
1.05-1.10 
Viscous 
Liquid 

Characteristic 
Below 50° F. 
40-75% 
60-90° F. 

5-15% 

98-100% 

0-2% 

0-1% 

0-2% 
65-95% 

Almost complete 
Almost complete 
Almost complete 

0.0% 

5-10% 
None 
None 

Trace to 5% 
10- 50% 
Up to 30% 
Yes 
No 
Yes 



According to Holde,^ on shaking wood tar with water, the aqueous extract 
will react acid (due to the acetic acid present), and upon adding a few drops of 
ferric chloride, will at first form a green and then a brownish-green coloration. 
On subjecting wood tar to distillation, the first portion passing over shows a sep- 
aration of water which will react acid. On continuing the distillation, oily matters 
are obtained dissolving readily in alcohol, and which on treatment with concen- 
trated sulphuric acid become converted into water-soluble substances. Pine tar 
has a high acid value, since it often contains as much as 30 per cent by weight 
of resin acids. 

Wood-tar Pitches. — Hard-wood-tar pitch and pine-tar pitch vary in 
their physical properties, depending upon the following circumstances: 

(1) The variety of wood used. 

(2) The method by which the wood is distilled, including the tem- 
perature, its duration, the kind of retort, etc. 

(3) The extent to which the tar is distilled in producing the pitch. 
The further it is distilled, the harder the pitch and the higher its fusing- 
point. 

They comply with the following characteristics: 

1 " Untersuchung der Kohlenwasserstoffole und Fette," p. 286. Berlin. 1913. 



192 



ASPHALTS AND ALLIED SUBSTANCES 



.- , J ^ Pine- tar Pitch 

Hardwood-tar ,. „ . 

„. , {from Resinous 

P'^tch „, ,> 

Wood) 

(Test 1) Color in mass Black Brownish black 

(Test 2) Homogeneity Uniform Uniform 

(Test 4) Fracture Conchoidal Conchoidal 

(Test 5) Lustre Bright to dull Bright to dull 

(Test 6) Streak Brown to black Brown 

(Test 7) Specific gravity at 77° F 1 . 20-1 . 30 1 . 10-1 . 15 

(Test 9c) Consistency at 77° F 10-100 10-100 

(Test 9d) Susceptibility factor > 100 > 100 

(Test 10) Ductility Variable Variable 

(Test 13) Odor on heating Characteristic Characteristic 

(Test 15a) Fusing-point (K. and S. method) 100-200° F. 100-200°F. 

(Test 16) Volatile matter Variable Variable 

(Test 19) Fixed carbon 15-35% 10-25% 

(Test 21a) Soluble in carbon disulphide 30-95% " 40-95% 

(Test 216) Non-mineral matter insoluble 5-70% 2-60% 

(Test 21c) Mineral matter 0-1% 0-1% 

(Test 22) Carbenes 2-10% 0-5% 

(Test 23) Solubility in 88° naphtha 15-50% 25-80% 

(Test 28) Sulphur 0% 0% 

(Test 30) Oxygen in non-mineral matter 1-5% 2-8% 

(Test 32) Naphthalene None None 

(Test 33) Paraffine None None 

(Test 35) Sulphonation residue 0-5% 0-3% 

(Test 37) Saponifiable constituents 5-25% 10-40% 

(Test 37c) Resin acids Up to 20% Up to 40% 

(Test 41) Diazo reaction Yes Yes 

(Test 42) Anthraquinone reaction No No 

(Test 43) Liebermann-Storch reaction Yes Yes 

A representative sample of hardwood-tar pitch tested by the author 
showed : 

(Test 9c) Hardness at 115° F 3.9 

Hardness at 77° F 53 . 1 

Hardness at 32° F Greater than 150 

(Test 9d) Susceptibility factor Greater than 100 

(Test 106) Ductility at 115° F 41 

Ductility at 77° F 50.5 

Ductility at 32° F . 

(Test 11) Tensile strength at 115° F 0.3 

Tensile strength at 77° F 2.1 

Tensile strength at 32° F 12.0 

(.Test 15a) Fusing-point (K. and S. method) 123° F, 

(Test 21a) Soluble in carbon disulphide 62 . 7% 

(Test 23) Soluble in 88° naphtha 25.3% 

A sample of pine-tar pitch tested by Church and Weiss ^ showed: 

(Test 7) Specific gravity at 77° F 1.13 

(.Test 96) Penetration at 115° F Too soft 

Penetration at 77° F 41 

Penetration at 32° F 3 

(Test 15c) Fusing-point (cube method) 127° F. 

(Test 19) Fixed carbon 19.9% 

(Test 21u) Soluble in carbon disulphide 95 . 4% 

(Test 216) Non-mineral matter insoluble 4.5% 

(Test 21c) Mineral matter 0.1% 

(Test 22) Carbenes 6.6% 

(Test 24) Soluble in benzol 92 . 2% 

»'*Some Experiments on Technical Bitumens," Proc. Am. Soc. Testing Materials, 15, 278, 1915. 



WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH 



193 



According to Benson and Davis, ^ wood-tar pitches are more soluble in acetone 
than in carbon disulphide. Thus, hard- wood-tar pitches were found to be 15.6- 
31.9 per cent more soluble in acetone than in carbon disulphide, and pine-tar pitches 
(obtained from the Douglas fir) 8.0 to 57.8 per cent more soluble in the former 
solvent. 

Wood-tar pitches are characterized by their extreme susceptibiUty 
to changes in temperature, by the fact that they appear hard and at the 
same time show a surprisingly low fusing-point.^ Wood-tar pitches are 
notoriously non-weatherproof. They are extremely susceptible to oxida- 
tion on exposure to the weather and soon converted into a lifeless and 
pulverent mass. Pine-tar pitch contains more or less resin, and accord- 
ing to Holde, shows an acid value greater than 57. 



ROSIN PITCH 

The sap of the long-leaf pine, known chemically as an oleo-resin, is 
composed of a mixture of spirits of turpentine and rosin. It is gathered 
by cutting into the bark one-half to one inch, whereupon the oleo-resin 
slowly exudes and is collected in small cups, of which various types are 
in use. 

The oleo-resin is then distilled to separate the spirits of turpentine 
from the rosin. The apparatus ordinarily used in the United States 




Fig. 79. — Retort for Distilling Rosin. 



for this purpose is shown in Fig. 79, consisting of a simple type of copper 
still with a " worm " condenser. The capacity of the still varies from 
10 to 40 barrels at the outside, and usually between 15 and 20. After 
the still is charged, the fire is started, and a mixture of spirits of turpen- 
tine and water (since the oleo-resin contains between 5 and 10 per cent 

» "The Free Carbon of Wood-tar Pitches," J. Ind. Eng. Chem., 9, 141, 1917. 

2 "Examination of Asphalts," by E. Donath and B. M. Margosches, Chem. Ind., 27, 220, 
1904; "Behavior of Wood-tar Pitch with Certain Organic Solvents," B. M. Margosches, Chem. 
Rev. Fett-Harz-Ind., 12, 5, 1905; "Distinction between Lignite Pitch and Other Pitches." by 
E. Graefe, C;»em. Zeit., 30, 298, 1906. 



194 ASPHALTS AND ALLIED SUBSTANCES 

of water) appears in the condenser. When all the water has boiled over, 
additional quantities are added in a small stream during the distillation, 
since the introduction of water causes the turpentine to boil at a lower 
temperature and prevents overheating, improving both the colors and 
yields of the turpentine and rosin. Towards the end of the distillation 
the stream of water is shut off, and the rosin heated until all the moisture 
is expelled, usually between 300 and 400° F. Before coohng, any foreign 
matter is skimmed off the surface of the rosin, after which it is strained 
through a fine mesh screen and barreled. ^ 

Rosin deprived of its turpentine, when heated in a closed retort will 
undergo destructive distillation, yielding a gas, an aqueous Hquor and 
an oily distillate which may be separated into several fractions. If 
the process is carried to completion, coke will be left as residue. If the 
distillation is terminated before the formation of coke, a pitchy residue 
will remain, known commercially as " rosin pitch." 

The rosin may be distilled either with or without superheated steam. 
If the latter is employed, the quality of the distillate is improved, and a 
much better temperature control obtained. Distillation under vacuum 
is also used in many cases. The rosin may accordingly be destructively 
distilled by any of the following processes: 

(1) At atmospheric pressure without steam. 

(2) With superheated steam. 

(3) Under vacuum. 

When the temperature of the rosin reaches 150° C. a liquid distillate 
appears which separates into two layers, the lower containing acetic 
acid, also other organic acids dissolved in water, and the upper composed 
of oily substances known as " rosin spirit " or " pinohne." When the 
temperature reaches 200° C. the receiver is changed, and the distillate 
which ensues is either collected together or separated into fractions. 
The temperature of the residue in the retort is permitted to reach 350 
to 360° C. but never to exceed the latter. The fraction between 200 and 
360° C. known as " rosin oil," may be separated into various portions 
termed " yellow rosin oil," '' blue rosin oil," " green rosin oil," etc., 
depending upon their respective colors. 

In distilling rosin destructively at atmospheric pressure, the following 
products are separated: 

Non-condensable gases 9 . 0% 

Acid liquor 3 . 5% 

Rosin spirits or pinoline 3 . 5% 

Rosin oil 67 . 0% 

Rosin pitch 16.0% 

Loss (rosin adhering to walls of still, etc.) 1 0% 

» Bulletin No. 229, U. S. Dept. of Agr., Wash., D. C, July 28, 1915. 



WOOD TAR, WOOD-TAR PITCH AND ROSIN PITCH 195 

According to Victor Schweizer,^ when rosin is distilled with super- 
heated steam, the following yields are obtained: 

Acid liquor 5.5- 5. 8% 

Rosin spirits 1 1 . 25-12 . 0% 

Blue rosin oil 49.0 -50.5% 

Brown rosin oil 10.25-10.65% 

Rosin pitch 18.0 -19 . 0% 

The rosin pitch is run from the still while it is hot, and allowed to 
cool in a suitable receiver. It is fairly uniform in composition and con- 
forms with the following characteristics: 

(Test 1) Color in mass Black 

(Test 2) Homogeneity Uniform 

(Test 4) Fracture Conchoidal 

(Test 5). Lustre Dull ' 

(Test 6) Streak Light yellow to 

brown 

(Test 7) Specific gravity at 77° F 1 . 08-1 . 15 

(Test 9c) Consistency at 77° F 50-100 

(Test 9d) Susceptibility factor Greater than 100 

(Test 10c) Ductility at 77° F 

(Test 14a) Behavior on melting Passes rapidly from 

the solid to the 
liquid state 

(Test 15a) Fusing-point (K. and S. method) 120- 200° F. 

(Testl6) Volatile matter, 500° F., 5 hrs 10-18% 

(Test 17) Flash-point Above 250° F. 

(Test 19) Fixed carbon 10-20% 

(Test 21rt) Soluble in carbon disulphide 98-100% 

(Test 21fc) Non-mineral matter insoluble 0-2% 

(Test 21c) Mineral matter 0-1% 

(Test 22) Carbenes 0-5% 

(Test 23) Solubility in 88° naphtha 90-100% 

(Test 28) Sulphur 0.0% 

(Test 30) Oxygen in non-mineral matter 5-10% 

(Test 33) Parafiine 0.0% 

(Test 35) Sulphonation residue 0-5% 

(Test 37) Saponifiable constituents 25-95% 

(Test 41) Diazo reaction Yes 

(Test 42) Anthraquinone reaction No 

(Test 43) Liebermann-Storch reaction Yes 

Rosin pitch is very much like rosin in its physical properties. It is 
extremely susceptible to temperature changes, and as ordinarily pro- 
duced, is hard and friable at 77° F. It is characterized by the presence 
of considerable quantities of unaltered resin acids (10 to 45 per cent), 
and is free from fatty acids, glycerol, sulphur and parafhne. It with- 
stands weathering very poorly, and has therefore but a limited use. 
Upon being heated, it passes rapidly from the solid to the liquid state, 
forming a melt of low viscosity. 

i"The Distillation of Resins," p. 59. New York. 



196 ASPHALTS AND ALLIED SUBSTANCES 

"Burgundy pitch" is the name applied to the oleo-resin which exudes from 
the Norway spruce {Abies excelsa), found in the Vosges Mountains and in the 
Alps; also from a species of pine obtained in the United States (Pinus australis). 
The crude oleo-resin is melted by boiling with water, and strained to remove any 
particles of bark or other impurities. It then constitutes the so-called "Burgundy 
pitch" {Pix ahietina), sometimes marketed under the name "Vosges pitch." These 
terms are misnomers, since the material is not a true " pitch," but in reality an oleo- 
resin. It contains more or less spirits of turpentine, which escaped expulsion during 
the boiling process, and a quantity of emulsified water imparting to it an opaque, 
yellowish-brown color. In consistency it is a more or less brittle sohd, largely 
susceptible to temperature changes. In summer it softens and gradually flows, 
and in winter it appears very hard and brittle. It melts easily, decrepitating 
because of the water present, and has a strong odor because of the the associated 
spirits of turpentine. On aging it loses its opacity, due to evaporation of the emulsi- 
fied water, and turns first to a translucent, and then to a transparent brown color, 
similar to that of rosin. Its composition is substantially the same as rosin, contain- 
ing in addition, spirits of turpentine and emulsified water. 



I 



CHAPTER XV 
PEAT AND LIGNITE TARS AND PITCHES 

PEAT TAR AND PEAT-TAR PITCH 



As previously stated (p. 59), peat is derived from the decom- 
position of vegetable matter in swampy places, such as marshes and bogs. 
On the surface we find the growing aquatic plants; somewhat deeper 
we find their decayed remains; and still deeper a dark colored pasty 
substance from which the vegetable structure has largely disappeared, 
containing a substantial percentage of moisture and constituting the 
crude peat. The plants which result in the formation of these deposits 
are mainly aquatic, including marine grasses, reeds, rushes, hedges and 
various mosses. The transformation is caused partly by oxidation in 
the presence of moisture, and also to some extent by the action of cer- 
tain forms of bacteria, moulds and fungi. As the mass of peat builds 
up in thickness, the lower layers are first compacted upon being subjected 
to pressure, and then gradually carbonized. The essential condition to 
peat formation is that the vegetable remains shall be deposited at a 
rate exceeding that of their decomposition. This does not prove to be 
the case in very warm climates, where the remains are entirely decomposed. 
The organic matter should only be partly decomposed, and since the prod- 
ucts of partial decomposition act as a preservative to inhibit further 
decay, we can readily understand why the building up of peat beds is 
cumulative. It progresses most rapidly at a mean atmospheric tem- 
perature of 45° F., which accounts for the fact that no peat bogs occur 
between the latitudes of 45° N., and 45° S. It is estimated ^ that there 
exist in the United States 20 million acres of peat bogs, 30 million acres 
in Canada, 50 milHon on the continent of Europe, also approximately 
3 milUon in Ireland. 

The following constitute the most important varieties of peat, based 
on the locaUty in which they are found: 

(1) "Hill peat" found at mountain tops and derived from plants consisting 
of Sphagnum and Andromeda mosses, likewise heath. 

(2) "Bottom peat," found near rivers, lakes, etc., in the low-lands, including: 
(a) dark peat approaching lignite in composition, occurring at the lower parts 

> Encyclopaedia Britannica, 11th Edition. 

197 



198 ASPHALTS AND ALLIED SUBSTANCES 

of the deposit; (6) middle peat, which is Hghter in color and in weight than the 
preceding; (c) the top stratum, which has a fibrous structure. 

Peat varies in color from light yellowish, through various tints of 
brown, to brownish black or black, all of which appear darker when the 
peat is moist. The lighter shades generally darken to brownish black 
or black upon exposure to air; due largely to oxidation. In texture, 
peat varies from light porous matter having a fibrous or woody structure, 
to substances which are amorphous and clay-Hke when wet, but appearing 
quite hard and dense upon drying. Peat may be classified as follows, 
based upon its physical characteristics: 

(1) Turfy peat, consisting of decomposed mosses and aquatic plants, having 
a yellow to yellowish-brown color, and a soft, spongy, or elastic structure, varying 
in specific gravity when dry from 0.11 to 0.26. 

(2) Fibrous peat, consisting of a distinctly fibrous structure derived from moss, 
grass, roots, etc., having a brown or black color. It is brittle and easily broken, 
much less elastic than turfy peat, and when dry has a specific gravity of 0.24 
to 0.67. 

(3) Earthy peat, forming earth-like masses when dry, and sometimes showing 
a vestige of fibrous structure. Fractures with more or less difficulty, presenting a 
surface with little lustre. Specific gravity 0.41 to 0.90. 

(4) Pitchy peat. Dense and hard when dry, resisting fracture and bre king 
with a smooth and often lustrous surface approaching that of lignite, Specific 
gravity 0.62 to 1.03. 

The chemical composition of peat is but little understood. It is 
regarded as a mixture of water, inorganic matter (calcium and iron 
compounds), vegetable fibres and humus acids (such as humic, ulmic, 
crenic, apocrenic, etc.). According to H. Borntrager ^ the black varieties 
contain between 25 and 60 per cent of humus acids, 30 to 60 per cent 
of fibre, and 3 to 5 per cent of ash. Nitrogenous compounds are also 
present varying from 1 to 3 per cent of the dry weight, resulting partly 
from the associated animal matter, and also due partly to the humus acids 
combining with atmospheric nitrogen, forming what are known as azo- 
humic acids. Sulphur is also present in amounts between 0.1 and 5.3 
per cent based on the dry weight. 

Resinous substances are found in certain varieties of peat to which 
various names have been assigned, also bodies of a waxy nature derived 
from the associated gelatinous algae, known as " sapropel." 

When recently formed, the peat beds are but loosely compacted, 
but as they accumulate, the under layers become compressed, so what 
once was a foot thick may be concentrated to several inches. In other 

^ Zeit. anal. Chem., 39, 694, 1900; 40, 639, 1901. 



PEAT AND LIGNITE TARS AND PITCHES 199 

cases the beds become covered with sedimentaiy rocks, which augment 
the pressm-e, and gradually transform the peat into hgnite.^ 

Peat is generally collected by cutting trenches through the bog with a spade, 
and removing it in sods about 3 to 4 ft. long. The deposits are worked in steps 
or tiers. Mechanical excavators and dredges have also been used for the purpose. 
The sods are allowed to drain, then air-dried and finally heated to a high tem- 
perature in either stationary or revolving ovens, to remove the water. Peat as 
freshly mined contains 75 and 90 per cent by weight of water, which must of 
necessity be removed before the product can be used as a fuel. Air-dried peat 
carries 10 to 15 per cent of moisture, and the artificially dried peat between a 
trace and 80 per cent of mineral ash, consisting principally of sand and clay with 
smaller quantities of iron oxide, calcium and magnesium salts. The maximum 
quantity of ash usually considered allowable when used as a fuel is 25 per cent 
of the dry weight. Peat with less than 5 per cent ash is considered good, between 
5 and 10 per cent as fair, and over 10 per cent as poor. With peat containing 
less than 10 per cent of ash in the moisture-free state, the fitted carbon varies 
between 15 and 35 per cent, averaging about 30 per cent. 

It is customary to briquette the partly dried peat, carrying 10 to 15 per cent 
of water, and then continuing the drying until practically all the moisture is 
removed, and the residual peat compacted into tough briquettes suitable for use 
as fuel. It is briquetted under a pressure of 18,000 to 30,000 lb. per square inch, 
which generates sufficient heat to liberate some of the tarry compounds of the 
peat, causing the sides of the briquettes to assume a highly polished glaze. The 
product is claimed to have a calorific value almost equal to that of coal. 

In 1904 Dr. M. E. Kenberg, of London, devised a process for dehydrating 
peat, known as "wet carbonizing," which seems to offer possibifities. The wet 
peat, containing 85 to 90 per cent of water, is subjected to a temperature slightly 
above 300° F., in a special form of apparatus, and under a pressure of 150 lb. 
This causes the peaty substances to coagulate and perhaps undergo a slight car- 
bonization, so that their phj'-sical properties become altered. The peat is darkened 
in color and transformed from a colloidal to a fine-grained form, which can readily 
be separated by filtering, so that the moisture in the filtered residue amounts to 
only 5 per cent. The process is continuous and the cost of operation low. 

The briquetted peat is ordinarily used directly as fuel, and to a hmited extent 
for the recovery of gas, tar, ammonium compounds and coke. Various methods 

1 "Reports upon the Irish Peat Industries," Hugh Ryan, Econ. Proc. Roy. Soc. Dublin, Part 
II, Vol. 1, pt. 13; E. Ries, 55th Ann. Rept. N. Y. State Mus., p. 55, 19.03; "Die Moore der 
Schweiz," Berne, Switzerland, 1904, issued by the Smith C4eological Commission, Chapter III 
contains a bibliography on peat; R. Chalmers on Canadi~an Peat, Min. Res. Canada, 1904; 
McCourt and Parmelee, Ann. Rept. State Geol., N. J., 1905; A. L. Parsons, 57th Ann. Ropt. 
N. Y. State Mus., Vol. 1, p. 16, 1905; "Peat and Its Products," by V. C. Kerr, 1905; J. A. 
Holmes, Bull. No. 290, U. S. Geol. Survey, Wash., D. C, 11-15, 1906; "Peat, Its Use and 
Manufacture," by P. R. Bjorling and F. T. Gissing, London, 1907; "The Data of Geochemistry," 
Clark, Bull. No. 330, U. S. Geol. Survey, Wash., D. C, 1908; "Peat and Lignite, Their Manu- 
facture and Uses in Europe," E. Nystrom, Dept. of Mines, Ottawa, Canada, Bull. 19, 1908; 
"Commercial Peat," by F. T. Gissing, 1909; "Investigation of the Peat Bogs and Peat Fuel 
Industry in Canada," Report 30 by Nystrom and Anrep, Ottawa, Canada, 1908; Report 71 by 
Anrep, Larson, Ekelund, etc., Ottawa, Canada, 1909-10; Report 266 by Anrep, 
1911-12; Report 351 by Anrep, Ottawa, Canada, 1913-14; "The Uses of Peat," by Chas. Davis, 
Bull. No. 16, Bureau of Mines, U. S. Dept. of Interior, Wash., D. C, 1911. 



200 ASPHALTS AND ALLIED SUBSTANCES 

have been used for distilling peat, similar to those employed for treating coal. 
Peat may be destructively distilled in closed retorts, obtaining a gas suitable for use 
as a fuel, likewise tar, ammonia, and a good grade of coke, but in the United 
States this process has only been carried on in a small experimental way. At the 
present time the cost of drying and briquetting peat brings its price higher than 
that of bituminous coal. For these reasons neither peat tar nor peat-tar pitch 
are produced in commercial quantities. It is probable, however, that in the future, 
greater attention will be paid to the enormous peat deposits now inoperative. A 
brief description of the European practice, therefore, will not be out of place. 

The Zeigler process of treating peat has attracted attention in Germany, Ba- 
varia, and Russia. It is distilled in retorts 40 ft. high, having an elliptical cross- 
section. The upper portion is constructed of cast iron and the lower of fire 
brick. Vertical fire-brick flues are built outside the central chamber. A feed-box 
is attached to the top of the retort with a gas-tight cover opening inward, and 
the lower portion of the retort terminates in a hopper with two openings from 
which the coke is removed from time to time. The volatile matter is drawn off 
by suction, passed through condensers to remove the aqueous liquor and tar, 
and the purified gases caused to burn in the fire-brick flues surrounding the retort. 
The products of combustion, having a temperature of 1800° F., are used for 
drying the peat until it contains about 15 to 20 per cent of moisture. The tar 
is separated from the aqueous liquor by heating the mixture with steam to the 
melting-point of the tar, which then rises to the surface. It is a black, viscid 
liquid with a disagreeable acrid odor, representing 2 to 5 per cent of the dry weight 
of the peat used. The aqueous liquor contains ammonium salts, acetic and other 
organic acids, wood alcohol> and pyridine bases. The tar is slowly distilled, and 
after the water ceases to pass over, the receiver is changed and the distillation 
continued until 45 per cent of oily distillate has been collected. The receiver is 
again changed, and heavy oils containing paraffine wax, totalling about 30 per 
cent by weight of the tar caught separately, leaving 15 to 20 per cent of peat-tar 
pitch in the retort, which is finally drawn off. The oily distillate first recovered 
is redistilled into light naphtha (density under 0.83), and heavy naphtha (density 
0.85). The heavy oil is cooled and pressed to separate lubricating oil from the 
paraflSne wax. The products are treated first with concentrated sulphuric acid 
and then with caustic soda to remove tarry impurities and creosote oil respectively, 
the latter being recovered in the form of creosote or carbolic acid. 

The following represent the percentages by weight of by-products obtained 
per ton of the air-dried peat: 

Gases and loss 15% 

Aqueous liquor 40% 

Peat tar 9% 

Coke 36% 

Total 100% 

The following percentages by weight of by-products were obtained from the 
aqueous liquor: 

Ammonium sulphate 4 . 0% 

Methyl alcohol 2.0% 

Pyridine bases 0.2% 

Acetic acid. . 1.5% 



PEAT AND LIGNITE TARS AND PITCHES 
The dry peat tar yields the following: 



201 





Crude, 
Per Cent. 


After Purification 
Per Cent. 


Light naphtha 

Heavy naphtha 

Lubricating oil 

Paraffine wax 

Peat-tar pitch 

Creosote 


16 
30 
15 
12 
16 


12 
25 
13 
2 
16 
12 
20 


Loss 


11 




100 


100 



Holde reports ^ that the destructive distillation crude un dried peat produces: 

Non-condensable gases , 12-21% 

Aqueous distillate 36-40% 

Peat tar 2-10% 

Briquetted Yorkshire peat on distillation yields between 11 and 22 lb. of ammo- 
nium sulphate per ton, and approximately 38 gal. of tar and water. The gases 
evolved are sufficient to conduct the process of distillation which yields a coke, 
hard enough to be used in blast furnaces. The tar on distillation yields the fol- 
lowing fractions: 

Below 150° C 1 . 35% distillate (sp.gr. . 867) 

150-250° C 29.90% distillate (sp.gr. 0.953) 

Above 250° C 50 . 00% distillate (sp.gr. . 941) 

Also a residue amounting to 18.75% of hard peat-tar pitch. 

The distillate boiling above 250° C. contained 6 per cent of paraffine wax. 

Graefe (loc. cit.) reports the following tests on Russian peat tar: 

Sp.gr 0. 936 

Boiling-point 195° C. 

Distillate of crude oUs 20% 

Peat-tar pitch 74 . 1 % 

Creosote in the crude oils 35% 

Paraffine in the crude tar 9 . 96% 

Fusing-point, of the crude tar 59 . 2° C. 

E. Bornstein and F. Bernstein ^ devised a process for subjecting crude peat 
to destructive distillation, and recover the nitrogenous compounds. The resulting 
tar after dehydration contained phenols, 18 per cent; nitrogenous bases (alka- 
loids), 1 per cent; neutral oils, 34 per cent; and pitch (containing paraffine), 
47 per cent. 

In Europe and Canada attempts have been made to utilize peat for manu- 
facturing producer gas (see p. 172). A special type of producer, known as the 
Korting "Double Zone, Up-draft Peat Gas Producer," has been designed for the 

1 Loc cit., p. 363. 

2 J. Gas Lighting, 129, 731, 1915; also Z. angew. Chem., 27, Aufsatz, 71-2, 1914. 



202 



ASPHALTS AND ALLIED SUBSTANCES 



purpose, 
for four 



as illustrated in Fig. 80. It operates on peat which has been air-dried 
weeks, containing 25 to 50 per cent moisture, thus saving the time 

and expense of drying artificially. This 
moisture is converted into steam in the 
producer, and obviates the necessity of 
introducing steam with the air, as in the 
case of coal or coke (p. 239). The air-dried 
peat B in the form of sods measuring 
8X4X2 in., weighing If to 2 lb. each, is 
charged into the hoppers A- A, from which 
it falls upon the sloping grates C-C, where 
it undergoes partial combustion. Sufficient 
air is admitted below the grates to distil off 
the moisture and volatile matter. The car- 
bonized fuel then passes downward through 
the comparatively narrow duct G to a second 
combustion zone H at bottom of the pro- 
ducer, where the combustion is carried to 
completion. The moisture and tarry vapors 
evolved in the upper zone pass through the 
opening D and downcomer E and intro- 
duced at F directly below the grate-bars 
of the lower zone, whence they pass upward 
through the incandescent fuel to the draw- 
off pipes J -J. The air admitted to the 
lower zone through the pipes /-/ is carefully 
regulated, so that a proper interaction will 
take place between the fuel, moisture, and 
tarry vapors, resulting in the ultimate forma- 
tion of hydrogen and carbon-monoxide. The 
tarry matters are partly converted into 
permanent gases, and partly burned. A good 
portion of the tar, however, escapes decompo- 
sition and is carried by the producer gas, from which it must be separated by a 
tar extractor and scrubber. The tar recovered in this manner amounts to 1 to 2 
per cent by weight of the dry peat and is very similar in composition and properties 
to peat tar derived from destructive distillation processes.^ 
Dehydrated peat tars in general, test as follows: 

(Test 1) Color in mass Black 

(Test 7) Specific gravity at 77° F 0.90-1.05 

(Test 9) Hardness or consistency Liquid 

(Test 15a) Fusing-point (K. and S. method) 40-60° F. 

(Test 16) Volatile matter at 500° F., in 4 hrs 50-85% 

(Test 17a) Flash-point 60-95° F. 

(Test 19) Fixed carbon 5-15% 

(Test 21a) Soluble in carbon disulphide 98-100% 

(Test 216) Non-mineral matter insoluble 0-2% 

(Test 21c) Mineral matter 0-1% 

(Test 22) Carbenes 0-2% 




Fig. 80. — Korting Double Zone Up- 
Draft Gas Producer for Peat. 



Use of Peat in Gas Producing Plants," E. C. C. Baly, J. Soc. Chem. Ind., 36, 1240, 1916. 



PEAT AND LIGNITE TARS AND PITCHES 203 

^Test 23) Solubility in SS° naphtha 95-100% 

(Test 28) Sulphur . Loss 1 % 

(Test 30) Oxygen in non-mineral matter 5-15% 

(Test 33) Paraffine wax 5-15% 

(Test 35) Siilphonation residue 5-15% 

(Test 37) Saponifiable constituents 5-15% 

(Test 41) Diazo reaction Yes 

(Test 42) Anthraquinone reaction No 

(Test 43) Liebermann-Storch reaction No 

Peat-tar pitch is obtained by the evaporation or steam distillation of peat tar. 
It is not an article of commerce in the United States. Its hardness or consistency, 
as well as its fusing-point, depend upon the extent to which the distillation has been 
conducted. Ordinarily peat-tar pitch tests much the same as lignite-tar pitch, 
the results being included on table XXXV, p. 482. It is highly susceptible to tem- 
perature changes, and withstands exposure to the weather very poorly. 



LIGNITE TAR AND LIGNITE-TAR PITCH 

The U. S. Geological Survey estimates that 1,087,514,400,000 tons of 
lignite are available in the Unite(i States, but it is used only in a Hmited 
\Yay, due to the abundance of other types of fuel.^ Large deposits occur 
also in Alberta, Saskatchewan and Manitoba, Canada. A zone covering 
about 1700 square miles has been located in Australia, and one small 
deposit has been reported in England (at Bovey-Tracey in Devonshire). 
A commercial product known as " kaumazite " is made from Bohemian 
lignite by a process of low-temperature distillation.^ In Germany, how- 
ever, the lignite industry has made much more rapid advances owing 
partly to the scarcity of high-grade coals, and partly to the fact that the 
deposits are located close to large cities, making the cost of transportation 
low. The lignite is accordingly used as a fuel for steam plants, for manu- 
facturing producer gas, and for distillation purposes to recover its valuable 
by-products. 

The descriptions of the methods which follow are based on German 
practice as carried out in the following localities, viz. : 

(1) near Horrem, a short distance west of Cologne in Rhine Provmce; 

(2) in the neighborhood of Halle on the Saale, in the Provinces of Saxony 

and Thuringia; and 

(3) at Messel, near Darmstadt in Hessen Province. 

The so-called browncoal (a variety of lignite) is mined at the first two 
localities. It is estimated that 20,000 to 25,000 tons were briquetted 
daily in the Cologne mining district alone, where the beds run from 30 

1 Charles A. Davis, Tech. Paper No. 55, Bureau of Mines, Dept. of Interior, W^ash., D. C, 
1913. 

2 Daniel Bellet, Rev. gin- Sci., 28, 118, 1917. 



204 ASPHALTS AND ALLIED SUBSTANCES 

to 350 feet thick, averaging 75 feet. Browncoal differs somewhat from 
American Hgnite in carrying a higher percentage of moisture (about 
60 per cent instead of 25 to 50 per cent). As mined, browncoal is soft 
and either unconsoUdated or but shghtly consoUdated, so that it can be 
cut easily with a knife. The Messel deposit carries about 30 per cent 
clay and 45 per cent water, the organic constituents apparently being 
combined chemically with the clay. It is greasy in consistency, having 
a black color with a greenish cast. The bed covers about 240 acres 
in a hemispherical depression, and measures 480 ft. in thickness under 
a cover 13 ft. thick composed of gravel and clay. 

Browncoal in the Cologne and Halle regions is found in stratified 
beds in which the layers alternately appear lighter and darker in color. 
The Hghter layers form a brownish-black plastic and greasy mass when 
freshly mined, and a yellowish to light brown pulverulent substance when 
dry. They are characterized by the presence of waxy constituents soluble 
in carbon disulphide, benzol, etc. The darker layers form a black plastic 
mass when fresh, and a dark brown to black earthy substance after dry- 
ing. They differ from the light-colored layers, in being substantially 
free from soluble waxy constituents. The two varieties are sorted during 
the process of mining. The light-colored product resembles the mineral 
pyropissite (see p. 160) but yields smaller percentages soluble in benzol, 
etc., the highest grade averaging 32.5 per cent (based on the dry weight). 

The lighter variety of lignite has been incorrectly termed '' bitu- 
minous lignite," and the darker, " non-bituminous lignite." For pur- 
poses of differentiation, we will refer to them as '' retort lignite " 
and " fuel lignite " respectively.^ Retort lignite ranges in specific 
gravity from 0.9 to 1.1 and melts at ignition, whereas fuel lignite has a 
gravity of 1.2 to 1.4, and does not melt. ' 

It is assumed that these two varieties of lignite, since they occur 
in the same deposit, result from differing conditions surrounding their 
formation, as for example a variation in water level. Thus if the original 
vegetable matter containing a large amount of waxy constituents was 
protected from the action of atmospheric oxygen by being surrounded 
with water until the transformation into lignite had been completed, 
then the woody tissue was more or less preserved, and fuel hgnite resulted. 
If, however, the water receded and exposed the deposit to the action of 
air, then the woody tissue became partly or wholly oxidized, leaving 
the more resistant materials behind, and resulting m the formation of 
retort lignite. If the process of atmospheric oxidation had been carried 
to the greatest possible extent, then the waxes only remain behind, in 

iln Germany they are termed "Distillation Coal" (Schwelkohle) and "Fire Coal" (Feuerkohle) 



PEAT AND LIGNITE TARS AND PITCHES 205 

the form of the mineral pyropissite. As stated previously, pyropissite 
is no longer mined, since its total available supply has been exhausted. 
Lignite as freshly mined is more or less rapidly acted upon by atmospheric 
oxygen, the dark variety being more susceptible than the light one. A 
typical Hgnite vein carries about twice as much fuel lignite as retort 
Hgnite. 

Retort lignite is treated in one or two ways, viz. : 

(1) It is subjected directly to low temperature destructive distil- 
lation, or 

(2) It is first extracted with a solvent to remove the montan wax and 
the residue either distilled destructively or briquetted and sold as fuel. 

Fuel lignite is also treated in one of two ways, viz.: 

(1) If it is comparatively free from ash, it is briquetted and used as fuel; 

(2) If it contains a large proportion of ash, as with Messel lignite, it is used 
for manufacturing producer gas by combustion in an atmosphere of air and steam, 
so that practically all the carbonaceous matter is consumed, leaving almost pure 
ash behind. Since Messel lignite in its crude state contains but 25 per cent of 
combustible material, it is unsuitable for use as fuel, or for purposes of destructive 
distillation. 

When the lignite is to be used for fuel, it is converted into briquettes by 
subjecting the granulated material to great pressure. The heat generated during 
this operation softens the waxy substances present, and binds the particles into 
a solid mass. It is unnecessary, therefore, to add any extraneous binding medium. 

Retort lignite is unsuitable for fuel or manufacturing briquettes, as the large 
quantity of waxy constituents present will soften when heated, causing the briquettes 
to melt and drop through the grate bars. When the retort lignite has been ex- 
tracted with solvents to remove the "montan wax," the residue still contains 
enough waxy constituents to enable it to be briquetted. 

Lignite is mined by the open-cut method where the over-burden is not very 
thick, or by driving shafts and tunnels when the bed is situated some distance 
below the surface. In the case of open-cut mining, the over-burden is first re- 
moved with steam shovels, and the lignite excavated by mechanically operated 
chain and buckets, which load the material into small skips. 

Shaft mining presents a number of difficulties owing to the softness and un- 
stability of the crude lignite. The shafts must be well timbered, and in many 
cases it is first necessary to freeze the lignite before it can be handled. This is 
accomplished by driving a series of vertical pipes at the bottom of the shaft 
through which salt solution cooled to a low temperature is caused to circulate. 
This soUdifies the lignite, and enables it to be be excavated without danger of 
cave-ins. 

Where the lignite is used for manufacturing briquettes, it is first crushed to 
about the size of peas, then passed through sieves, and finally through a drier 
to reduce the moisture to approximately 15 per cent. A tubular drier, heated 
with steam, has been found most satisfactory for the purpose.^ The lignite powder 

1 " Briquetting Tests of Lignite at Pittsburgh, Pa.," Bulletin No. 14, Bureau of Mines, U. S. 
Dept. of Interior, Wash., D. C, 1911. 



206 



ASPHALTS AND ALLIED SUBSTANCES 



is fed into a briquetting press, -v^here it is subjected to a pressure between 18,000 
and 22,500 lb. per square inch.^ 

When the retort hgnite is to be subjected to destructive distillation, 
it is used directly as it comes from the mine, without drying. In fact, 
the presence of the water materially assists the distillation process by 
preventing the volatile products from decomposing too extensively. 
The water is converted into steam which quickly removes the vapors 
from the hot retort and prevents cracking. Practice has shown that 

the moisture content should 
not be less than 30 per cent. 
In distilHng hgnite, the humic 
acids present are converted 
into the so-called " neutral 
bodies," the cellulose deriv- 
atives into phenolic bodies 
and unsaturated hydrocar- 
bons, and the waxy constitu- 
ents into saturated hydro- 
carbons and paraffine wax. 

It is claimed that the 
Rolle retort shown diagram- 
matically in Fig. 81 has been 
found most satisfactory for 
treating hgnite. It is 5 to 
6 ft. in diameter by 20 to 
25 ft. high, and works con- 
tinuously, the operation pro- 
gressing in two stages, viz.: 

(1) Drying the lignite. 

(2) Decomposing the lig- 
nite into gas, water, tar and 
coke. 

The contrivance is com- 
posed essentially of two con- 
centric cylinders, an outer 
one of fire brick and an inner 
one consisting of a stack of 

conical rings assembled in louvre fashion, constructed of iron or fire clay. 

The hgnite after being crushed into lumps about IJ to 2i in. in diameter is 

1 "The Production and Use of Browncoal in the Vicinity of Cologne, Germany," by C. A. 
Davis, Tech. Paper No. 55, Bureau of Mines, U. S. Dept. of Interior, Wash., D. C, 1913. 




Fig. 81. — Retort for Distilling Pure Lignite. 



PEAT AND LIGNITE TARS AND PITCHES 



207 



introduced into the space between the concentric cyhnders. The products 
of distillation pass out through the flues A and B. The openings C 
represent the fire-flues; D, the stack of conical rings; E, the cap covering 
the rings; F, an inverted cone of metal into which the coke falls after 
the lignite has been thoroughly carbonized; G, a device for intermittently 
drawing off the coke; H, the combustion chamber; J, vents for intro- 
ducing the gases; K, the pipes through which the gases enter; and L, 
the fire place which comes into play when the retort is first started up. 
Coal or Hgnite is burnt on the grate, until the process of destructive 
distillation commences, whereupon the resulting non-condensable gases 
are introduced through K and J, and caused to burn in the flues C. The 
space over the cap E is kept filled with lignite, and the rate of travel 
through the retort is controlled by the frequency with which the coke 
is removed from the chamber G. 

The temperature at which the distillation takes place varies between 
500 and OOO"" F., and the vapors issue from the retort at 250 to 300° F. 
The products of decomposition are drawn from the retort by a shght 
suction, and passed through a series of air condensers, which removes most 
of the tar, the high boiling-point oils, and part of the water. The condensa- 
tion is completed by passing the gases through pipes surrounded by water. ^ 
The tar is separated from the condensed water by warming it and allowing 
it to stand quietly in a suitable receptacle. The tar being fighter than the 
water, rises to the surface, and is drawn off when the separation is complete. 

In recent years the following percentages have been recovered: 

Water 50-60% 

Tar 5-10% 

Coke 25-35% 

Gas Balance 

The coke has a more or less granular structure, and after quenching with water, 
carries about 20 per cent of moisture and 15 to 25 per cent of ash, depending 
upon the character of the raw Hgnite. 

The following figures show the yield on distilling an exceptionally rich lignite 
containing 32.5 per cent of constituents soluble in carbon disulphide, which inci- 
dentally, is very much higher than the present run of the mines: 





Original Lignite, 
Per Cent. 


Lignite after Extrac- 
tion with Solvents. 
Per Cent. 


Montan Wax 
Extracted, 
Per Cent. 




9 
23 
33 
35 


12 
19 

21 

48 


5 


Aoueous liauor 


5 


Tar 


78 


Coke 


12 






Total 


100 


100 


100 







Die Braunkohlenteer-Industiie," by Ed. Graefe. Halle a. S. 190G. 



208 



ASPHALTS AND ALLIED SUBSTANCES 



In Southern Saskatchewan, Canada, the raw Hgnite tests as an average: 
water, 26.13 per cent; volatile hydrocarbons, 28.11 per cent; fixed carbon, 38.16 
per cent; ash, 6.86 per cent; and sulphur, 0.74 per cent. It is treated in a ver- 
tical chamber oven, like a horizontal by-products oven, charged and discharged 
continuously. The gradual application of heat increases the yield of hydrocarbon 
by-products at a high speed of treatment. Rapid evolution of gas results at 
700-900° F., and ceases at 1000° F. A ton of the crude lignite yields: gas, 10,000 
cu. ft.; crude tar (water-free), 15 gal.; ammoniacal liquor, 65 gal.; and coke, 
955 lb. On distillation, the tar yields: light oils, 11.5 per cent; creosote oils, 13.5 
per cent; parafiine, 34.1 per cent; and hard pitch, 24.5 per cent. About 15 lb. 
of ammonium sulphate are recovered per ton.^ 

The Messel lignite carrying a large percentage of mineral water is 
treated in a special form of retort built in batteries, as illustrated in Fig. 

82. The process takes place in three 
stages, viz.: 

(1) Drying of the lignite and accom- 
panying generation of steam, taking 
place in the zones c. 

(2) Distillation of the dried material, 
taking place in zones b, 

(3) Combustion of the residual coke 
by means of air and the steam generated 
in (1), taking place in zones a. The steam 
liberated in zones c is passed through the 
flues G-e, f-f, and G-g respectively into 
the zones a, as illustrated. 

In other words, the steam generated 
by the lignite itself, is used to decompose 
the coke into producer gas, as described 
on p. 172. The gas is caused to burn 
in the chambers A, B and C respectively, 
the products of combustion passing 
through the openings o, o. Pipe d repre- 
sents the outlet for the products of 
decomposition, and s represents the sup- 
ply pipe for the heated gas. The paths 
of the products are indicated by the 
arrows. The yield of tar varies between 
4 and 14 per cent, averaging about 7i 
per cent (19 gallons per ton), that of gas 6 per cent, water 44 per 
cent and coke 36 per cent. The residue discharged from the bottom 




Fig. 82.— Retort for DistiUing 
Impure Lignite. 



»" Methods of Utilizing Lignite," S. M. Darling, J. Gas Lighting, 131, 456, 1915. 



PEAT AND LIGNITE TARS AND PITCHES 209 

of the retort is composed of mineral matter carrying 8 per cent of unde- 
composed carbon. More gas is generated during the process than is 
required for heating the retort, and the excess is used for other purposes. 

Lignite in either the air-dried or briquetted form is gradually being 
used more and more, especially in Europe, for manufacturing producer 
gas. Either a Westinghouse double-zone gas producer (see p. 242) or 
a Korting double-zone up-draft producer may be used. The latter is 
similar in construction to the Korting peat-gas producer (Fig. 80), but 
the channel is greater in cross-section, and steam must be introduced 
with the air below the grate-bars in the lower zone when artificially dried 
briquetted Hgnite is used. About 60 cu. ft. of gas are produced from 
each pound of the dry hgnite, also i to | per cent by weight of hgnite 
tar, which is separated from the producer gas in the usual manner. When 
the air-dried lignite is used, the process is very similar to that which takes 
place in the Messel retorts, but the yield of tar is much smaller since 
the moisture and tarry vapors generated in the upper part of the pro- 
ducer are passed through the incandescent lignite from below, to decom- 
pose the tar as much as possible, and correspondingly increase the yield 
of producer gas. In other words, the Messel retort is designed primarily 
to recover the tar, and the hgnite-producer to generate gas. 

Lignite tar has a buttery consistency at ordinary temperatures 
with a dark brown to black color. It is composed of Uquid and solid 
members of the paraffine and olefine series, together with a small quantity 
of the benzol series, also the higher phenols and their derivatives. It is 
characterized by the presence of a substantial proportion of solid par- 
affine (10 to 25 per cent) and from 0.5 to 1.5 per cent of sulphur. 

In general, dehydrated lignite tar conforms with the following char- 
acteristics: 

(Test 1) Color in mass Yellowish brown to 

greenish brown to 
brownish black 

(Test 7) Specific gravity at 77° F . 85-1 . 05 

(Test 9) Hardness or consistency at 77° F Salve-hke to buttery 

(Test 10) Ductility at 77° F None 

(Test 13) Odor on heating Characteristic 

(Test 15a) Fusing-point (K. and S. method) 60-90° F. 

(Test 16) Volatile matter at 500° F., 4 hrs 70-85% 

(Test 17o) Flash-point (Pensky-Martens tester) 75-90° F. 

(Test 19) Fixed carbon 5-20% 

(Test 20) Distillation test The boiling point ranges 

between 80 and 400° 
C, the greater por- 
tion distilling between 
250 and 350° C. 

(Test 21a) Soluble in carbon disulphide 98-100% 

(Test 216) Non-mineral matter insoluble 0-1% 

(Test 21c) Mineral matter 0-1% 

(Test 22) Carbenes 0-2% 



210 



ASPHALTS AND ALLIED SUBSTANCES 



(Test 23) Solubility in 88° naphtha 95-100% 

(Test 28) Sulphur 0.5-1.5% 

(Test 29) Nitrogen Less than 0.1% 

(Test 30) Oxygen 5-10% 

(Test 31) Free carbon 0-1% 

(Test 32) Naphthalene ^-1% 

(Test 33) Paraffine 10-25% 

(Test 35) Sulphonation residue 10-20% 

(Test 37) Saponifiable constituents 5-20% 

(Test 41) Diazo leaction Yes 

(Test 42) Anthraquinone reaction No 

(Test 43) Liebermann-Storch reaction No 

Graefe reports ^ that destructively distilled lignite tar will range as follows: 



Good Tar. 



Average Tar. 



Poor Tar. 



Specific gravity at 77' F 

Commences to boil 

Crude oil distillate 

Parafl&naceous residue 

Paraffinaceous residue solidifies at. 
Creosote in crude oil distillate. . . . 
Creosote in paraffinaceous residue. 
Paraffine in paraffinaceous residue. 

Paraffine in the tar itself 

Fusing-point of the paraffine 



0.867 
190° C. 
30% 
63% 
29.8° C. 
11.0% 
9.0% 
23.3% 
14.67% 
51.0° C. 



0.886 
130° C. 

371% 
55.5% 
25.8° C. 
15.0% 
6.0% 
5-22.0% 
2-12.5% 
46.7° C. 



0.917 
174° C. 
24.1% 
68.9% 
26.1° C. 
19 . 5% 
7.0% 
18.2% 
12.53% 
52.7° C. 



The aqueous liquor separated from the lignite tar contains 0.03 to 0.07 per 
cent of ammonium salts, which are so small in amount that it scarcely pays to 
recover them. Lignite contains an average of 0.3 per cent of nitrogen, which is 
distributed among its products of distillation as follows: viz. The gas contains 
12 per cent, the aqueous Uquor 12 per cent, the tar 10 per cent, and the residual 
coke 66 per cent. 

In practice, lignite tar is distilled to separate various oils and paraffine 
wax. The distillates are purified by treatment with acids and alkali, 
and the paraffine by re-crystallization. 

The distillation is conducted in one of three ways, viz. : 

(1) At atmospheric pressure, without steam. 

(2) By means of steam. 

(3) Under vacuum, sometimes supplemented with steam. 

Vacuum distillation is generally used, as it saves fuel, reduces the 
time and prevents cracking of the distillates. The best practice consists 
in using a slight vacuum at the beginning of the distillation, and gradually 
increasing it until the paraffine begins to distil, when it is maintained at 
16 to 28 in. of mercury by a steam injector, or vacuum pump. 

With steam distillation, either plain or superheated steam may be used, 
and direct heating of the retort may be dispensed with in the latter case 

The distillation may be intermittent or continuous. European prac- 
tice provides for the continuous distillation of the dehydrated tar in a 

1 " Laboratoriumsbuch fiir die Braunkohlenteer-Industrie," Halle a. S., p. 38, 1908. 



PEAT AND LIGNITE TARS AND PITCHES 211 

vertical cylindrical still with a hemispherical bottom having a dome- 
shaped cover carrying the exit pipe and fastened to the body of the still. 
Each still is connected with a condenser composed of a circular coil of 
metal piping immersed in a water tank. Between 10 and 20 stills are 
erected side by side on a common brick setting. 

Gases derived from the destructive distillation of the lignite, are mixed 
with air and allowed to burn in flues underneath and around the stills. 

Lignite tar is first distilled to J its original bulk, and the combined 
residues of several stills are run into a separate retort. In some cases the 
residues are distilled to produce lignite-tar pitch, but in the majority they 
are distilled until nothing but coke remains. By thus treating the 
residues in separate retorts, the Hves of the first retorts are lengthened 
materially, and the wear and tear concentrated on a few. The retorts 
in which the preliminary distillation takes place are of course subjected 
to a much lower temperature than those in which the residues are treated. 

When lignite tar is distilled to coke, a certain amount of cracking 
occurs, and consequent formation of tarry matter in the distillates, which 
is removed by treating with sulphuric acid, and the resulting sludge 
worked up into lignite-tar pitch as will be described later. 

Obviously the pitches derived in these two ways differ in their phys- 
ical properties, and particularly in the quantity of associated paraffine, 
which is smaller in lignite-tar-sludge pitch. 

The tar is fractioned into crude oil (about 33 per cent), a paraffinace- 
ous distillate (about 60 per cent), red oil (about 3 per cent), permanent 
gases (about 2 per cent) and coke (about 2 per cent). 

The crude oil is re-distilled into naphtha, illuminating oil, cleaning oil, 
gas oil and light paraffine oil (vaseline oil). The paraffinaceous mass 
is cooled and pressed, which removes the heavy paraffine oil from the 
paraffine wax. The paraffine wax is then re-crystallized and separated 
into the soft paraffine wax and hard paraffine wax respectively. 

According to Scheithauer (loc. cit.), an average grade of lignite tar 
will yield the following products, viz.: benzine 5 per cent, lubricating 
oil 5 to 10 per cent, light paraffine oils 10 per cent, heavy paraffine oils 
30 to 50 per cent, hard paraffine 10 to 15 per cent, soft paraffine 3 to 6 
per cent, dark-colored products 3 to 5 per cent, coke, gas and water 20 
to 30 per cent. 

If the distillation of lignite tar is not continued to coke, lignite-tar 
pitch is obtained, amounting to about 5 per cent by weight of the tar. 

The following diagram shows the essential steps in treating lignite 
tar by fractional distillation, including the two alternatives of running 
to pitch and coke respectively. 



212 



ASPHALTS AND ALLIED SUBSTANCES 



■0- 



-©- 



O a 



§ ^ 











^^ 


H r^ 




a 5 


173 


^■^ 


w 






^§1 




1 h~ 


01 


C4 Ih 


fl 


^5 


56 

c3 




-*.^ S 


03 r^ 


S^ 


^ O 


o 


— ^ >> « 


M 


> .5 





H ? 



- Q 

C5 tJ 



fSO 



k:) '^ 



.9 O 
6 M 



^1 

a o 

1 S,- 

" TO 



^ a 



<i3 ii 



13 
73 S 



_ 4) 






I a 



PEAT AND LIGNITE TARS AND PITCHES 



213 



The fractions are purified by treating successively with sulphuric acid and 
caustic soda, which improves the color and odor, and enables the products to com- 
mand a higher price. The steps in refining include: 

(1) Treatment with 50° Baume sulphuric acid. 

(2) Treatment with 66° Baume sulphuric acid. 

(3) Washing with hot water. 

(4) Treatment with a small volume of 38° Baum^ caustic soda. 

(5) Treatment with a large volume of 38° Baume caustic soda. 

(6) Washing with hot water. 

The preliminary treatment with weak sulphuric acid removes a portion of the 
basic constituents, including the pyridine. The stronger sulphuric acid extracts 
the remaining basic substances, the tarry matters which impart a dark color, a 
portion of the unsaturated hydrocarbons and the resinous constituents. The small 
quantity of alkali serves to neutralize the acid, and the larger quantity to remove 
the creosote oils which would impart a disagreeable odor and darken on exposure 
to Hght. 

The chemical treatment is carried out in lead-lined steel vessels, and the mixing 
effected with a current of air. 

The following represent roughly the quantities of acid and alkali required to 
purify the various fractions: 



Naphtha 

Illuminating Oil. . . 

Cleaning Oil 

Soft paraffine wax. . 
Hard parafl&ne wax. 



50° B6. 

Sulphuric Acid, 

Per Cent. 



66° B6. 

Sulphuric Acid, 

Per Cent. 



38° B6. 

Caustic Soda, 

Per Cent. 



The total quantity of sulphuric acid required to refine the various fractions 
varies between 6 and 7 per cent by weight of the tar, and that of caustic soda 
between 1 and 1| per cent. 

The following refined products are obtained: 

Naphtha. Specific gravity, 0.800-0.820; flash-point, 25-35° C; boiling commences 
at 136° C, 7 per cent distils under 150°, 12 per cent distils under 200°, and the 
balance under 250° C. 

Illuminating Oil. Specific gravity, 0.820-0.835; flash-point, 35-50° C; boiling 
commences at 136° C, 4 per cent distils under 150°, 84 per cent distils under 
200°, and the balance under 250° C. 

Cleaning Oil. Specific gravity, 0.835-0.860; flash-point, 60-70° C; boiling com- 
mences at 189° C, 4 per cent distils under 200°, 95 per cent distils under 250°, 
and the balance under 300° C. It is free from paraffine wax. 

Gas Oil. Specific gravity, 0.875-0.900; flash-point, 80-90° C; ignition-point, 
100-120° C; boiling commences at about 200° C, 20-30 per cent distils under 
250" C, and 70-80 per cent under 300° C. 

Light Paraffine Oil. Specific gravity, 0.900-0.915; flash-point, 90-100° C; 
ignition-point, 130° C; boiling commences at 210-220° C, 2 per cent distils 
under 250° C, and 33 per cent distils under 300° C 



214 ASPHALTS AND ALLIED SUBSTANCES 

Heavy Paraflne Oil Specific gravity, 0.915-0.930; flash-point, 100-110° C; 
ignition-point, 130-165° C; boiling commences at 230° C, 2 per cent distils 
under 250° C, and 16 per cent distils under 300° C. 

Paraffine Wax. Fusing-point varies from 35 to 62° C. (K. and S. method). 
Soft paraffine wax is understood to fuse below, and hard paraffine wax above 50° 
C. The crude wax flashes between 160 and 165° C. Its specific gravity varies 
with the fusing-point, ranging between 0.880 and 0.915. 

The tar produced from Messel lignite is treated in a similar manner, but only 
the first fraction of the distillate is refined with chemicals, using approximately 
2 per cent of sulphuric acid and 3 per cent of caustic soda. 



After the chemical treatment, the acid and soda sludges are settled 
off. The acid sludge is boiled v^ith steam in lead-lined vessels, which 
decomposes it into pitch and sulphuric acid (30 to 40° Baume). This 
acid has a dark brown color and is used for decomposing the soda sludge 
into creosote oil and sodium sulphate (glauber salt) . The impure creosote 
containing tarry matters is mixed with the pitch separated from the acid 
sludge, and after washing with water to remove all traces of acid and 
alkali, the mixture is distilled with superheated steam. The purified 
lignite creosote is recovered as distillate (having a specific gravity of 
0.940 to 0.980, and yielding 50 to 70 per cent soluble in caustic soda) 
and the lignite-tar pitch rernains as residue. The extent to which the 
distillation is continued regulates the hardness and fusing-point of the 
pitch, which is much harder in consistency than that obtained from the 
direct distillation of lignite tar.^ 

Lignite-tar pitch is characterized by the presence of phenols giving the diazo 
reaction, the absence of anthracene (as determined by the anthraquinone test), 
the absence of insoluble carbonaceous matter, the presence of small quantities of 
paraffine wax, and the fact that it is largely soluble in 88° naphtha. These tests 
distinguish it from coal-tar products. 

According to Graefe,^ lignite-tar pitch is almost completely soluble in benzol 
and turpentine, and less soluble in petroleum ether or naphtha. Donath and Mar- 
gosches ^ report that lignite-tar pitch is partly dissolved on boiling with a solution 
of alcohoHc potash. 

i"Die Braunkohlenteer-Industrie," by Dr. Ed. Graefe. Halle a. S., 1906; "Die Braunkohlen- 
teerprodukte und das Oelgas," by Dr. W. Scheithauer, 1907; "Peat and Lignite, Their Manufacture 
and Uses in Europe," by E. Nystrom, Report 19, Dept. of Mines, Ottawa, Canada, 1908; "Die 
Schwelteere, Ihre Gewinnung und Verarbeitung," by Dr. W. Scheithauer, 1911; "Shale Oils and 
Tars," by Dr. W. Scheithauer, London, 1913; "Peat, Lignite and Coal," by B. F, Haanel, Re- 
port 299, Dept. of Mines, Ottawa, Canada, 1913; "Methods of Utilizing Lignite," by S. M. 
Darling, J. Gas Lightinp, 131, 456, 1915; "The Investigation of Six Samples of Alberta Lignites," 
by Haanel and Blizard, Report 331, Dept. of Mines, Ottawa, Canada, 1915; "The Brown Coal 
Distillation Industry of Germany," by D. R. Steuart, J. Soc. Chem. Ind., 36, 167, 1917. 

2 " Laboratoriumsbuch fur die Braunkohlenteer-Industrie," p. 139, 1908. 

^Chem. Ind., 27, 220, 1904; also J. Soc. Chem. Ind., 23, 541, 1904. 



PEAT AND LIGNITE TARS AND PITCHES 215 

Lignite-tar pitches conform with the following tests: 

(Test 1) Color in mass Black 

(Test 2) Homogeneity Uniform 

(Test 3) Appearance surfaceaged indoors one week Dull 

(Test 4) I racture Conchoidal 

(Test 5) Lustre. Very bright when fresh 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity at 77° F 1 . 05-1 . 20 

(Test 9c) Hardness at 77° F., con.?!istometer 10-100 

^Test 9d) Susceptibility factor Greater than 100 

(Test 10) Ductility Variable 

(Test 13) Odor on heating Characterislic 

(Test 14o) Behavior on melting Passes rapidly from a solid 

into a liquid state 

(Test 15a) Fusing-point (K. and S. method) 90-250° F 

(Test 16) Volatile matter Variable 

(Test 17o) Flash-point Usually above 250° F. 

(Test 19) Fixed carbon 10-40% 

(Test 21o) Solubility in carbon disulphide 95-99% 

(Test 216) Non-mineral matter insoluble 0-2% 

(Test 21c) Mineral matter 0-1 % 

(Test 22) Carbenes 0-5% 

(Test 23) Solubility in 88° naphtha 75-95% 

(Test 25) Solubility in other solvents Largely soluble in benzol 

and turpentine 

(Test 28) Sulphur Less than 2 . 5% j 

(Test 30) Oxygen in non-mineral matter 2-5% 

(Test 31) Free carbon Trace 

(Test 32) Naphthalene Absent 

(Test 33) ParafEne 1-5% 

(Test 35) Sulphonation residue 5-15% 

(Test 37) Saponifiable constituents 0-5% 

(Test 41) Diazo reaction Yes 

(Test 42) Anthraquinone reaction No 

(Test 43) Liebermann-Storch reaction No 

Lignite-tar pitch is distinguished from wood-tar pitch by its associated sulphur 
and paraffine wax; from coal-tar pitch by its almost complete solubility in benzol 
and carbon disulphide; and from asphalt, resin pitch and fatty-acid pitches by 
the diazo reaction. On destructive distillation, lignite-tar pitch yields an oily 
distillate free from acid, whereas wood-tar pitch yields an aqueous distillate with 
an acid reaction.^ 

In Germany, where practically all of the lignite-tar pitch is produced, it is 
used extensively for manufacturing cheap paints in consequence of its solubility 
in petroleum distillates. 

1 "Distinction between Lignite Pitch and Other Pitches," by E. Graefe, Chem. Zeit., 30, 298, 1906; 
"Native and Artificial Asphalts," by J. Marcusson and R. Eickmann, Chem. Re-:. Fett.-Harz-Ind., 15, 
315, 1908; "Identifying Asphalts," by J. Marcusson, Chem. Rev. Fett-Harz-lnd., 18, 47, 1911; J. 
Soc. Chem. Ind., 30, 480, 1911; "Chemical Composition and Examination of Natural and Artificial 
Asphalts," by J. Marcusson, Chem. Rev. Fett-Harz-lnd, y 19, 166, 1912. 



CHAPTER XVI 
SHALE TAR AND SHALE-TAR PITCH 

The most important deposits of asphaltic and non-asphaltic pyro- 
bituminous shales have been considered in Chapter XII. Scotland is 
the home of the " shale oil " industry. According to Bacon and Hamor ^ 
four large Scottish companies are operating at present, with works at 
Pumpherston, Oakbank, Roman Camp, Broxburn, Dalmeny, Bathgate, 
Uphall, Addiewell, Deans and Seafield, Scotland. At Dorsetshire, 
England, shales are also being worked. 

They are mined in the same manner as bituminous coal, by driving 
shafts, and then extending drifts radially. Considerable timbering is 
necessary, on account of the softness of the shale. When the seams are 
over 4 ft. in thickness, they are mined by the " pillar " and " stall " 
method, and when less than 4 ft. thick, by the " longwall " method. 

The mineral as mined is hauled to the surface by power, and then 
run through a breaker, where the masses are broken into lumps measuring 
4 to 6 in. in diameter. The breakers consist of a number of toothed 
iron discs mounted on two shafts revolving in opposite directions. The 
shale upon being crushed to the proper size, is next conveyed up an incline 
to the top of the retort. 

Retorts Used for Distillation. The retorts used have been modified 
from time to time to increase their efficiency, add to their durability, 
hasten the speed of treatment, or to improve the quality of the output. 

The basic principle underlying the modern retort was embodied to 
the patent originally granted to Young & Beilby,^ illustrated in Fig. 83. 
This consists of four vertical cylinders mounted together, with a common 
hopper above. The upper portion of each cylinder is constructed of metal, 
and the lower portion of fire brick. The distillation takes place in the upper 
part of the retort where the shale is heated to 900° F. The shale is then 
subjected to a higher temperature (1300° F.) in the lower portion, which 
is in reality a gas producer, steam and air being admitted to convert 
the carbonaceous residue into carbon dioxide and carbon monoxide. 
This generates sufficient heat to effect the distillation in the upper portion 

'"American Petroleum Industry," Vol. 2, p. 810, 
JEng. Pat. No. 4284 of 1881. 

1 216 



SHALE TAR AND SHALE-TAR PITCH 



217 



of the retort. The admission of air is carefully regulated to maintain 
the required temperature, without causing excessive combustion of the 
by-products. The steam also serves to convert the nitrogen into ammonia. 
The charge gradually passes downward in the retort at a speed regu- 
lated by the periodical removal of the. spent shale below. This type wa,s first 
used at Oakbank, but was open to the criticism that it was difficult to 




From "The American Petroleum Industry," by Bacon and Hamor. 
Fig. 83.— Young & Beilby Retort for Distilling Shales. 

control the temperature of the upper and lower portions respectively. 
Thus, if the lower portion became too hot, the shale would fuse and the 
retort become chocked up. This resulted in several modifications forming 
the basis of the modern retort which is embodied in four different types, 
viz.^ : 

Piunpherston Type of Retort used at Pumpherston, Oakbank, Dalmeny Deans 
and Seafield, Scotland. This was disclosed in Eng. Pats. No. 8371 of 1894, and 
No. 7113 of 1895, granted jointly to Bryson and Eraser (of the Pumpherston Oil 
Co., Limited) and to Jones (of the Dalmeny Oil Works); also Eng. Pat. No. 4249 

»*' American Petroleum Industry, " "by Bacon and Hamofj Vol. 2, p. §IQ; also "Shale Oils 
and Tara," by Scheithauer, p. 41, 1913. 



218 



ASPHALTS AND ALLIED SUBSTANCES 




of 1897, granted to Bryson. The shale is 
prevented from fluxing and choking up 
the retort by keeping it moving continu- 
ously instead of intermittently as in the 
Young and Beilby retort. This is brought 
about by supporting the column of shale 
on a disc, from which a revolving scraper 
discharges the consumed shale into the 
hopper below. This retort is illustrated 
in Fig. 84, The shale is introduced into 
the charging hopper, c whence it passes 
into the upper cast-iron portion of the 
retort a in which the actual distillation 
takes place. The shale then slowly works 
its way into the lower portion h, con- 
structed of fire-brick, and finally into the 
lower hopper d extending underneath sev- 
eral retorts, converging in such a manner 
that a single line of rails running below 
the centre will permit the exhausted shale 
to discharge into small cars, e represents 
the metal disc at the bottom of the retort, 
and i the revolving arm or scraper. Steam 
is introduced into the lower portion of 
the retort 6 a short distance above the 
disc e, and the gaseous products of distil- 
lation are burned with air in the external 
flues to maintain the retort at the proper 
temperature. 

Young and Fyfe Type of Retort used 
at Bathgate, Uphall and Addiewell, Scot- 
land. This is embodied in Eng. Pats. No. 
13,665 of 1897, and No. 15,238 of 1899 
issued to William Young and John Fyfe, 
and consists of a large multiple charging 
hopper bolted to a vertical metallic section 
which in turn connects with a lower fire- 
brick section of the same diameter, having 
a spacious combustion chamber at the 
bottom. The shale is introduced con- 
tinuously into the retort from the hoppers 
by means of two sets of cams attached 
to rocking-shafts which rise and fall alter- 
nately, thus obviating the stoppage of the 
retort due to the shale fusing fast to the 
entrance of the metallic section. A me- 
chanical device is also provided at the 
lower end of each retort to effect a con- 
tinuous discharge of the spent shale into 



Fig. 84. — ^Pumpherson Retort for 



SHALE TAR AND SHALE-TAR PITCH 



219 



the combustion chamber, which receives the spent shale in a highly heated con- 
dition, and enables the carbonaceous matter to be consumed by introducing steam 
and air. The danger of the shale fluxing and attaching itself to the side-walls 
of the retort is thus minimized. 

Henderson Type of Retort used at Roman Camp and Broxburn, Scotland. 
This is described in Eng. Pats. No. 6726 of 1889, and 26,647 of 1901, granted to 
N. M. Henderson (of the Broxburn Oil Co., Limited), and illustrated in Fig. 85. 
Four retorts are mounted together. The upper cast-iron portion (a) is supported 
directly by the fire-brick section b, the joint between the two being formed so 




Fig. 85. — Henderson Retort for Distilling Shales. 



as to obviate leakage, which is the source of more or less trouble in the other 
types. This retort is made comparatively long to heat the shale gradually and 
thus diminish wear and tear on the lining. The column is kept in' continuous 
motion by a pair of revolving toothed rollers i at the bottom, which discharge 
the spent shale into a metal hopper d, whence it passes into small cars. The gases 
escape through the flue e into the pipe /. The yield of ammonia is high and the 
recovered tar of good quality. 

Del Monte Type of Retort Used at Dorsetshire, England. This retort is heated 
internally by burning a portion of the non-condensable gases in a flue extending 
through the centre of the charge of shale. The retort is inclined at an angle of 



220 ASPHALTS AND ALLIED SUBSTANCES 

15® to the horizontal, and the shale introduced at the lower end and worked up- 
ward by a spiral screw. The non-condensable gases are passed into the upper 
portion of the retort together with sufficient air to support combustion and forced 
downward to the cooler end where the products of distillation are partly con- 
densed by coming in contact with the cold shale. The shale is distilled at the 
lowest possible temperature, for the purpose of increasing the yield of tar.^ 

Methods of Recovering Shale Tar. The vapors leaving the retorts 
are first passed through an " economizer," consisting of a tower filled 
with pipes, around which cold water is circulated and thus preheated for 
use in the steam boilers (see Fig. 60). The vapors are then passed 
through an air-condenser (Fig. 59) which separates most of the tar and 
ammoniacal hquor. They are next passed through a scrubber (filled with 
a checker-work of wood), and finally through a naphtha scrubber where 
they are washed with the " intermediate oil " obtained in distilling the 
shale tar (having a high boiling-point and a specific gravity of 0.84 to 
0.86) which extracts any fight naphtha not previously condensed (about 
2 gal. per ton of shale). The naphtha is separated from the scrubbing 
oil by heating the mixture moderately in a still, and condensing the 
distillate (having a specific gravity of 0.73). 

The crude tar and ammoniacal liquor are allowed to stand in a suit- 
able container, whereupon the tar rises to the surface on account of its 
lower gravity, and is drawn off. The crude tar is generally termed 
'' shale oil," but this name is just as inappropiiate as the expression 
'^ oil shale," often used to designate the shale (see p. 158). 

Products Obtained and Their Yields. Upon destructively distilling 
the Kimmeridge Shales of England and the Lothian Shales of Scotland, 
the following products are obtained: 

(1) Non-condensable gases, averaging 3000 cu. ft. per ton. 

(2) Ammoniacal Hquor yielding an average of 45 lbs. ammonium 
sulphate per ton. 

(3) Shale tar, averaging 25 gal. per ton. 

(4) Light naphtha, averaging 2 gal. per ton. 

(5) Spent shale, averaging between 80 and 85 per cent of the raw 
shale, and containing approximately 2J per cent unconsumed carbon. 

The non-condensable gases are burned under the retorts, and the 
spent shale discarded, as it has no further value. The valuable products 
are the light naphtha, the shale tar and ammonium sulphate. 

The ammoniacal liquor separated from the tar is treated with steam 
under a pressure of 20 to 30 lbs. in a tower filled with baffle-plates. The 
liquor is run in at the top and the steam introduced at the bottom. The 

»W. H. Mansfield, J. Inst. Petrol. Techn., 2, 162, 1916; Engineering, 101, 164, 1916. 



SHALE TAR AND SHALE-TAR PITCH 



221 



ammonia is expelled in the gaseous state and recovered by passing it 
into sulphuric acid contained in a vessel known as a " cracker box." 
The acid used for this purpose is usually the waste product from the 
refining process. Crystals of ammonium sulphate separate when the liquor 
becomes sufficiently concentrated, and after being dried are m.arketed 
as such. In this manner the ammonia is separated from the other nitro- 
genous bases, including pyridine, contained in the aqueous liquor. 

The following table gives the minimum and the maxinmm yields of 
dehydrated shale tar in gallons, and ammonium sulphate in pounds per 
ton of shale, obtained from the most important shale deposits in different 
parts of the world. ^ As a matter of interest, figures are included showing 
the yields from grahamite (West Virginia), albertite (New Brunswick), 
stellarite (Nova Scotia), coorangeite (Australia), torbanite (Scotland), 
and pyropissite (Halle, Germany), although these are no longer distilled 
commercially because most of the deposits have long been exhausted. 



Yield of Shale Tar 
(in Gallons). 



Yield of Ammonium 
Sulphate (in Pounds). 



Grahamite (West Virginia) 

Albertite (New Brunswick) 

Stellarite (Nova Scotia) 

Torbanite (Scotland) 

Coorganite (Australia) 

Pyropissite (Halle, Germany) 

Lothian shale (Scotland) 

Kimmeridge shale (England) 

Coorangitic shale (New South Wales) 

Orepuki shale (New Zealand) 

Albert shale (New Brunswick) 

Arcadian shale (Nova Scotia) 

Shales (Eastern United States) 

Utah shales 

Colorado and Wyoming shales 



170-200 
90-112 
50-130 
90-130 
80-120 



65 



10-55 

10-40 

14-150 

20-40 

30-51 

4-23 

4-45 

6-10 

10-68 



6-70 
10-50 
20-30 



67-111 

9-40 

0-10 

40-50 

22-34 



Properties of Shale Tar. Shale tar usually appears black in mass 
with a greenish fluorescence. It is similar in composition to lignite tar, 
although differing from the latter in containing a larger percentage of 
nitrogen (1.1 to 1.5 per cent). Members of the paraffine and olefine 
series constitute 80 to 90 per cent by weight of the tar, and small 
quantities of cresols and phenols are present. 

Dehydrated shale tar tests as follows: 

(Teat 1) Color in mass , Brownish black with a 

greenish fluorescence 
(Test 7) Specific gravity at 77° F 0.85-0.95 

» "American Petroleum Industry," by Bacon and Hamor, Vol. 2, p. 832; "Oil Resources of 
Black Shales of the Eastern United States," G. H. Ashley, Bulletin 641-L, U. S. Geol. Survey, 
Wash., D. C, 1917. 



222 ASPHALTS AND ALLIED SUBSTANCES 

(Test 9) Hardness or consistency Salve-like to buttery 

(Test 15o) Fusing-point (K. and S. method) 60-90° F. 

(Test 16) Volatile matter at 500° F., 4 hrs 80-90% 

(Test 17a) Flash-point (Pensky-Martens tester) 20-60° F. 

(Test 19) Fixed carbon 5-10% 

(Test 21a) Soluble in carbon disulphide 98-100% 

(Test 216) Non-mineral matter insoluble. 0-2% 

(Test 21c) Mineral matter 0-1% 

(Test 22) Carbenes 0-2% 

(Test 23) Soluble in 88° naphtha 95-100% 

(Test 28) Sulphur 1.5-2.5% 

(Test 29) Nitrogen Tr.-1% 

(Test 30) Oxygen 1-5% 

(Test 31) Free carbon 0-2% 

(Test 33) Paraffine 5-15% 

(Test 35) Sulphonation residue 15-35% 

(Test 37) Saponifiable constituents 0- 2% 

(Test 41) Diazo reaction . Yes 

(Test 42) Anthraqainone reaction No 

(Test 43) Liebermann-Storch reaction No 

The percentage of phenols contained in the shale tar is very much smaller 
proportionately than that present in peat or lignite tars. Shale tar is distinguished 
from the latter by containing larger percentages of nitrogen and sulphur, and 
smaller percentages of oxygen, paraffine and phenols respectively. 

Refining of Shale Tar. Shale tar may be distilled either inter- 
mittently or continuously. In either case the process consists in heating 
the tar in a still to expel the moisture, whereupon either plain or super- 
heated steam is introduced through a perforated pipe under a pressure 
of between 10 and 40 lbs. The tar is evaporated to dryness and the 
following products separated: 

(1) Non-condensable gases ranging from 1 to 2 cu. ft. for each gallon 
of shale tar. 

(2) Light naphtha having a specific gravity of 0.74 to 0.76. 

(3) So-called '' once-run oil '' or " green oil " representing the 
fraction between the light naphtha and coke. 

(4) A residue of coke approximating 3 per cent by weight of the 
shale tar. 

The steam is shut off towards the end of the distillation, after the 
" once-run oil " has passed over. 

The stills used in Scotland are of the vertical type from 2000 to 2500 
gal. capacity, constructed of a hemi-spherical cast-iron bottom, and a 
soft malleable-iron cylindrical body to which is attached a dome-shaped 
top bearing the exit pipe. Each still is connected with its own condenser. 

In the continuous distillation process termed the " Henderson Proc- 
ess"^ a battery of three horizontal stills and one vertical pot-still is used. 
The tar is first led into the middle still where the naphtha is distilled off, 

lEng. Pat. No. 13,014 of 1885. 



SHALE TAR AND SHALE-TAR PITCH 223 

and the residue caused to flow continuously into the two side stills. 
These are heated higher than the centre still, causing the one-run oil 
to distil over continuously. (See continuous distillation of petroleum, 
p. 273.) The residues from these second stills are led into the pot- 
still, where they are evaporated to dryness, the distillate being condensed 
and united with the once-run oil. Several pot-stills are used, since the 
red-hot coke must be allowed to cool before it can be removed, which 
prevents this part of the process being continuous. 

The once-run oil is refined by agitating it with sulphuric acid at 100° 
F. by compressed air. The acid sludge is run off, the oil washed with 
water, and then treated in another agitator with caustic soda in a similar 
manner. 

The refined once-run oil is fractioned either by an intermittent or 
continuous steam distillation process, the following products being 
recovered : 

(1) Heavy naphtha varying in gravity between 0.75 and 0.77. 

(2) Illuminating oil, varying in gravity between 0.78 and 0.85, and having a 
flash-point of 125° F. 

(3) Intermediate or gas-oil varying in gravity between 0.85 and 0.87, and 
having a flash-point higher than 150° F. This is used for manufacturing water- 
gas or enriching illuminating gas (p. 231). 

(4) Lubricating oil having a gravity from 0.87 to 0.91. 

(5) Crude paraffine wax which is purified by re-crystallization or "sweating," 
having a fusing-point between 110 and 130° F. 

(6) Still grease, which represents the distillate passing over at the close of 
the distillation. , 

The various distillates, with the exception of the still grease are 
refined further with sulphuric acid and caustic soda, similar to the method 
used for treating the once-run oil. The crude paraffine wax is refined 
by the sweating process as described on p. 307. 

The following yields are obtained from Scotch shale tar: 

Heavy and light naphthas 3-6% 

Illuminating oil 20-30% 

Intermediate or gas-oil 10-25% 

Lubricating oil 15-20% 

Soft paraffine scale 3-5% 

Hard paraffine wax 7-9% 

Non-condensable gases 3-5% 

Acid and soda sludges and losses 20-25% 

The acid and soda tars obtained from the various refining processes 
are mixed together in such proportions that the free acid and alkali 
will exactly neutrahze each other. The resulting sludge is ordinarily 
used as fuel for the stills, but experiments have been made to convert it 



224 ASPHALTS AND ALLIED SUBSTANCES 

into pitch suitable for use as a wood preservative, pipe-dip, or the base of 
bituminous paints. Comparatively little has been accomplished in this 
direction, probably due to the fact that other products are available 
for these purposes, costing but little more and possessing superior weather- 
resisting properties. " Shale-tar pitch," is very similar in its physical 
properties and composition to lignite-tar pitch (see p. 215). 



CHAPTER XVII 

COAL TAR AND COAL-TAR PITCH 

Under the headings '' Coal tar " and '^ Coal-tar pitch ," will beincl uded 
the tars and corresponding pitches recovered as by-products from bitu- 
minous coal in: 

(1) Gas works; 

(2) Coke ovens; 

(3) Blast furnaces; 

(4) Gas producers. 

Water-gas tar and water-gas-tar pitch have been included by some 
writers within the scope of the terms coal tar and coal-tar pitch respec- 
tively, but in this treatise they will be considered separately since they 
differ in their composition and properties, due to the use of petroleum 
products in their manufacture, as described on p. 258. 

It is estimated that of the total production of coal tar in the United 
States in 1916 (about 225,000,000 gal.), 22 per cent (or 50,000,000 
gal.) was obtained as a by-product in the manufacture of coal gas 
in gas-works, and the balance as a by-product from coke ovens. The 
amounts obtained from gas producers and blast furnaces are practically 
negligible. The three main sources of coal tar in the order of their 
importance are: first, coke-oven coal tar which is continually increasing 
in quantity; second, horizontal retort gas-works coal tar, which has not 
materially increased during the past few years on account of the growing 
popularity of water gas; and third, a comparatively smaller, but gradually 
increasing amount of vertical retort gas-works coal tar. 

Bituminous coals only are suitable for the production of coal tar. 
Cannel and anthracite coals will not answer, since the former distils 
at too low a temperature, and the latter contains insufficient volatile 
matter. Experiments show that cannel coals from Missouri and Illinois 
on distillation yield 28.1 to 69.7 gal. tar and 3500 to 8100 cu. ft. rich 
gas per ton. Between 450 and 500° C, the maximum gasolene is pro- 
duced, between 550 and 650° C, the maximum kerosene, and above 
650° C. soft paraffines, heavy lubricating oils, kerosene and asphalt- 

225 



226 ASPHALTS AND ALLIED SUBSTANCES 

like bodies.^ Bituminous coals are known as '^ gas coals " when used 
for manufacturing illuminating gas, and " coking coals '^ when used for 
coking. Western Pennsylvania, West Virginia, Virginia, eastern Kentucky 
and Tennessee produce most of the bituminous coals used for these pur- 
poses, and they comply with the following characteristics: 

Air-dry loss of coarse material 1 -5% 

Moisture at 105° C. (powdered material) 1 . 5-7 . 0% 

Volatile matter on ignition 20 -40% 

Fixed carbon 50 -75% 

Ash Less than 15% 

Sulphur Less than 2% 

Hydrogen 4.5-5.5% 

Carbon 65 -85% 

Nitrogen 1 -2% 

Oxygen 5-15% 

Very little is known regarding the chemical composition of the bitu- 
minous coal itself, due to the difficulty in converting the coal into recog- 
nizable derivatives, and because of its slight solubility in the usual 
solvents for bituminous materials. On subjecting coal to high tempera- 
tures, the bodies present decompose into simpler substances which fail 
to give any clue as to their original structure and comxposition. Recent 
researches lead to the conclusion that coal is essentially a conglomerate 
of cellulose decomposition products admixed with altered resins and 
gums originally present in the plants from which the coal was derived. 

The substances having the highest solvent action are pyridine, ^ which dissolves 
15 to 35 per cent by weight of bituminous coal; aniline,^ which dissolves 20 to 
40 per cent; phenol,* which extracts 25 to 40 per cent at a temperature of 110° 
C; and quinoline,^ which extracts 30 to 50 per cent at its boiling-point. Anthra- 
cite coal is scarcely acted upon by these solvents.*' 

A method has recently been devised for converting coal into soluble derivatives ^ 
by subjecting the finely pulverized coal suspended in water to the action of ozone 
at room temperature. It is stated that at the end of two days, 92 per cent of 
the coal dissolves, forming a solution having a dark brown color. It would seem 
that some very promising results may be obtained by this method. 

It has been shown ^ that the soluble portion of bituminous coal when subjected 

i"Studiea in the Production of Oils and Tars from Bituminous Materials," J. C. Ingram, 
8. of M. and Metallurgy, Univ. of Mo., Bull. 4, Vol. 3, May, 1917. 

2 Bedson, /. Soc. Chem. Ind., 18, 739, 1899; Baker, J. Soc. Chem. Ind., 20, 789, 1901; 27, 147, 1908; 
"The Action of Solvents on Coal," Anonymous, J. Soc. Chem. Irid., 35, 1136, 1916; A. Wahl, "The 
Solvents of Coal," Bull. Soc. Chim., 21, 76, 1917. 

3 Vignon, J. Soc. Chem. Ind., 33, 633, 1914. 

* Frazer and Hoffman, Tech. Paper 5, Bureau of Mines, U. S. Dept. of Interior, Wash., D. C, 
1912; Parr and Hadley, J. Soc. Chem., Ind. 34, 213, 1915. 

6 Vignon, J. Soc. Chem. Ind., 33, 633, 1914. 

6/. Soc. Chem. Ind., 35, 634, 1917. 

'Franz Fisher, Ber., 49, 1472, 1916; Engineering, 103, 296, 1917; J. Ind. Eng. Chem., 9, 
620, 1917; Chem. Ahs., 11, 1739, 1917. 

8 Clarke, Wheeler and Piatt, Chem. Soc. Trans., 103, 1713, 1913; J. Soc. Chem. Ind., 32, 
969, 1913. 



COAL TAR AND COAL-TAR PITCH 227 

to destructive distillation yields petroleum-like bodies, whereas the insoluble portion 
yields phenols and their derivatives.^ 

D. T. Jones ^ examined the tars derived from the destructive distillation of 
bituminous coal in vacuo at very low temperatures (below 450° C). These were 
then subjected at atmospheric pressure to successively increased temperatures up 
to 800° C. Unsaturated hydrocarbons, naphthenes, paraffines, phenols, aromatic 
hydrocarbons and pyridines were found to be present in the low-temperature tar, 
whereas benzol and its homologues, naphthalene, anthracene, phenanthrene and 
the solid aromatic bodies were absent. As the temperature was increased, the 
naphthenes, paraffines, and unsaturated hydrocarbons were transformed into olefines. 
As the temperature was further increased, the olefines were in turn transformed into 
benzene and its homologues. The percentage of olefines appears to reach a maxi- 
mum at 550° C, and a minimum at 750° C, at which latter temperature hydrogen 
and naphthalene are rapidly evolved, as well as methane. The conclusion reached 
is that ordinary coal tar obtained from bituminous coal at high temperatures results 
chiefly from the decomposition of the tar previously formed at lower temperatures. 

The commercial processes for obtaining coal tar will now be considered. 

Production of Gas-works Coal Tar. In manufacturing illuminating 
gas, bituminous coal is heated in comparatively small fire-clay retorts, 
of D-shaped, oval or round cross-section about 16 to 24 in. in diame- 
ter. The D-shaped retort is ordinarily used in modern gas-works because 
it is least liable to distortion under the action of heat, and moreover 
presents the greatest area at its base, enabling the contents to be 
heated more rapidly. In some cases the retorts are '' single-ended," 
measuring 8 to 9 ft. in length, but modern practice favors the use of 
" double-ended " retorts composed of three sections joined together, 
measuring 15 to 25 ft. over all. In the single-ended retort a metal mouth- 
piece is bolted to one end, to which in turn the gas outlet pipe is fast- 
ened. With the double-ended retort, metal mouth-pieces are bolted fast 
to both ends. From 6 to 9 retorts are set together in a common brick 
setting, constituting a " bench " which is heated by a single furnace. 

The retorts are supported in either a horizontal, inclined or vertical 
position. The inclined or vertical retorts seem to meet with greater 
favor since they avoid overheating, prevent the formation of " free 
carbon " in the tar, and at the same time permit the coke to be handled 
by gravity. The vapors leave horizontal retorts at 600 to 800° F. and the 
vertical and inchned retorts at 300 to 400° F. 

The retorts are heated with water-gas obtained by passing air and 

1 See also Jones and Wheeler, Chem. Soc. Trans., 107, 1318, 1915; J. Soc. Chem. Ind., 34, 
1043, 1915. 

2 "The Thermal Decomposition of Low Temperature Coal-tar," /. Soc. Chem. Ind., 26, 3, 
1917; see also "The Primary Volatile Products of the Carbonization of Coal," by H. C. Porter, Chem. 
Abs., 11, 2537, 1917. 



228 



ASPHALTS AND ALLIED SUBSTANCES 



gteam through incandescent coke beneath the " bench." The coke used 
for this purpose is derived as a residue from a previous charge of bitu- 




-h.e,^^- 



minous coal, amounting to 15 to 25 per cent of the total coke produced. 
The water-gas is burnt in flues surrounding the retorts and the process 
of combustion controlled by the introduction of air. This method of 



COAL TAR AND COAL-TAR PTICH 



229 



firing results in a higher and more uniform temperature with the minimum 
consumption of fuel. The temperature in the combustion chamljer 
ranges from 2800 to 3200° F., and in the flues surrounding the retorts 
from 1900 to 2200° F. An improved installation of horizontal retorts 

is shown in Fig. 86, inchned 
retorts in Fig. 87, and vertical 
retorts in Fig. 88. Continuously 
operating vertical retorts are now 
being adopted extensively, in 
which the coal is fed through 
the retort in a constant stream, 
the coke being withdrawn con- 
tinuously at the bottom. These 
include the Woodall-Duckham 
and Glover- West types. 

Formerly the retorts were 
charged and discharged by hand, 
using a shovel and rake respect- 
ively. Mechanical devices are 
now used for the purpose, the 
double-ended horizontal retorts 
being charged at both ends with 
a scoop fed from an overhead 
hopper, operated either by com- 
pressed air or electricity. About 
600 lb. of coal are introduced 
into the double-ended retort, and 
subjected to heat from 3 to 6 
hours. The inclined and vertical 
retorts are charged through the 
top and discharged by gravity 
from the lower end. Horizontal 
retorts are discharged by a 
pneumatic or an electrical driven 
ram, which forces out the coke 
at the farther end. Inchned 
retorts are set at an angle between 25 and 35° which is sufficient to 
enable the coal to feed into the lower end, where it is held in place 
by a metal cover. In the inchned and vertical types the volatile constit- 
uents are withdrawn from the upper end. 

The vapors are subjected to the highest temperatures in the hori- 




FlG 



From "Coal and Coke," by F. H. Wagner. 
87. — Inclined Gas- Works Retort. 



230 



ASPHALTS AND ALLIED SUBSTANCES 



zontal retort, due to the longer contact with the heated internal surfaces, 
which results in a larger percentage of free carbon, and a tar of higher 
specific gravity. 

Methods of Recovering Gas-works Coal Tar. The volatile products 
pass from the retort into the hydraulic main (see p. 174), which forms a 
water-seal, permitting any retort to be charged, and at the same time 
preventing the gas generated in the other retorts escaping through the 







f — — ^^ r^^wf ffT"^ 

Fig. 88.— Vertical Gas-Works Retort. 



open one. The hydrauHc main reduces the temperature of the vapors 
to 130 to 160° F. 

The methods for separating tar from the gaseous constituents have 
already been described on page 174. After leaving the hydraulic main 
the vapors are subjected to the toUowing treatment in modern gas-works: 

(1) The gases are passed through a "primary condenser" which may either be 
air-cooled or water-cooled, or both (see p. 175). 

(2) The gases are then passed through a tar-extractor, usually of the P. & A. 
type (Fig. 69). 



COAL TAR AND COAL-TAR PITCH 231 

(3) Next passed through an exhauster to relieve the pressure on the retorts 
and force the gases through the ensuing train of apparatus. 

(4) The gases are next passed through two "scrubbers" (p. 177), prefer. biy 
of the rotary type illustrated in Fig. 65. In the first scrubber the gases are washed 
with a heavy tar oil, such as anthracene oil, to remove the naphthalene, and in 
the second with an alkaline solution of ferrous sulphate to remove the cyanogen. 

(5) The gases are then cooled to about 60° F. by passing them through a 
"secondary condenser," similar to the first one. 

(6) The ammonia is next removed by passing the gases through a third scrubber 
through which a stream of water is allowed to trickle. Formerly a tower scrubber 
filled with a checker-work of wooden boards (Fig. 63) was used for this purpose, 
but this is being replaced by a rotary scrubber similar to that used for extracting 
the naphthalene and cyanogen. 

(7) The last step consists in passing the gases through a series of "purifiers," 
consisting of low cylindrical chambers filled with trays or sieves. Some of the 
purifiers are filled with slaked lime to remove carbon dioxide and a portion of 
the sulphur compounds, and others with iron oxide to remove the remainder of 
the sulphur compounds (mostly hydrogen sulphide). 

The following percentages of tar are collected from the hydraulic 
main, condenser, washer and scrubber, also the tar extractor respectively: 

Hydraulic main 61% 

Condenser 12% 

Washer and scrubber 15% 

Tar extractor 12% 

Total 100% 

The operations which take place in the final handling of illuminating gas 
before it enters the mains, cease to be of interest in relation to the pro- 
duction of tar, and will accordingly be omitted. 

In the United States, temperatutes to which the retorts are heated vary 
from 900 to 1500° C. Between 900 and 1000° C. is known as low tem- 
perature treatment, from 1000 to 1100° C. medium temperature, and from 
1100 to 1500° C. high temperature treatment. In England the average 
temperature is 1100° C. In Germany horizontal retorts are heated 
between 1000 and 1100° C, and inclined retorts between 1100 and 1200° C. 
The quantity and yield of the tar depend largely upon the temperature 
(see p. 168). In the low temperature production of illuminating gas, 
an average of 16 gal. of tar is produced per ton of coal, and in high 
temperature processes an average of 8. The maximum variation ranges 
between 4 and 20 gal. of tar per ton. High- temperature processes are 
preferable, as they increase the yield of gas, but have the disadvantage of 
reducing its illuminating power. It is often necessary, therefore, to enrich 
the illuminating gas resulting from the high temperature processes by one 
of the following methods: 



232 ASPHALTS AND ALLIED SUBSTANCES 

(1) Heating the gas with a portion of the tar recovered during 
its manufacture, either by passing both together through superheaters, 
or else cracking the tar alone and then mixing the resulting permanent 
gases with the low illuminating power coal gas. 

(2) Mixing the coal gas with oil gas obtained by cracking crude 
petroleum at a high temperature. (See p. 259). 

(3) Saturating the coal gas of lower illuminating power with vapors 
of volatile hydrocarbons such as benzol, etc. 

(4) Mixing the coal gas with carburetted water gas. (See p. 256.) 
The following represent the yields from an average grade of bituminous 

coal in manufacturing illuminating gas. 

Gas 17% UO.OOO cu. ft.) 

Aqueous liquor 8% 

Tar 5% 

Cok3 70% 

Total , 100% 

Of course, these figures are subject to variation, and depend upon 
the quality of bituminous coal used, the temperature at which it is dis- 
tilled, etc. Thus the yield of gas per ton of rich coal will vary from 
5000 to 15,000 cu. ft., and the residual coke from 55 to 75 per cent. 

The illuminating power of the gas depends upon the quantity of hydrocarbons 
present, including both unsaturated and saturated. The hydrogen and carbon 
monoxide act as combustible diluents, and do not contribute to the luminosity 
of the flame. The carbon dioxide, nitrogen, and oxygen may be regarded as im- 
purities. The chief unsaturated hydrocarbons present are ethylene, butylene, acet- 
ylene, benzol and naphthalene, and the chief saturated hydrocarbons are methane 
and ethane. In certain cases benzol is extracted from the coal gas, being marketed 
as "gas-benzol," which constitutes a most valuable raw material for manufacturing 
coal-tar dyes, chemicals and drugs. High-grade gas coal yields approximately | to 
1 per cent by weight of gas-benzol, equivalent to 2-3 per cent by weight of the 
coal gas.^ 

The aqueous liquor, known as "gas liquor," contains a series of ammonium 
compounds dissolved in water, including the sulphide, carbonate, chloride, thio- 
cyanide, sulphate, thiosulphate and ferrocyanide. The ammonia is derived from 
the nitrogen in the coal, only part of which is carried in the aqueous liquor. The 
following table will give a general idea of the distribution of nitrogen among the 
various products of destructive distillation: 

Nitrogen in gas . 72% 

Nitrogen in aqueous liquor: 

As ammonia 14 50% 

As cyanides 1 . 56% 

Nitrogen in tar 34 . 54% 

Nitrogen in coke 48 . 68% 

100.00% 
lApplebee, J. Soc. Ckem. Ind., 12, 635, 1917. 



COAL TAR AND COAL-TAR PITCH 233 

The tar collected from the hydraulic main, condenser, washers and 
scrubbers is run into wells constructed of metal or masonry, sometimes 
heated with steam-coils (p. 181) and allowed to settle as long as possible, 
to permit the aqueous liquor, which is hghter than the tar, to rise to the 
surface, where it is drawn off and treated separately to recover the 
ammonium compounds. The well-settled g^s-works tar carries between 
4 and 10 per cent of water. In exceptional cases the water may run as 
high as 40 per cent, although this is not regarded with favor. The settled 
tar is shipped direct to the distilling plant, where it is dehydrated. 

Production of Coke-Oven Coal Tar. As stated previously, about 78 
per cent of the coal tar produced annually in the United States is 
obtained from coke-ovens equipped to recover by-products. This only 
represents betw^een 40 and 50 per cent of the total quantity of bitumin- 
ous coal converted into coke. The remaining 50 to 60 per cent is 
coked in brick " beehive " ovens, constructed in the form of a beehive, 
and not adapted to recover the gas, ammonia or tar, which are allowed 
to burn away through an opening in the top of the oven, thus constitut- 
ing a reckless waste of our national resources, running into many millions 
of dollars annually. For years this wasteful practice remained unchecked, 
but happily the present tendency is to replace the beehive ovens with 
types adapted to recover by-products, and it is probably only a matter 
of a few years more before all the coke-ovens will be equipped to recover 
the gas, ammonia and tar. 

In European countries, on the other hand, where the tendency has 
always been towards a greater economy, coke-ovens have long been 
perfected to recover these by-products. In this connection it nmst be 
borne in mind, whereas it is absolutely necessary to remove the tar in 
manufacturing coal gas for illuminating purposes, this does not prove to 
be the case where the coal is converted into coke for metallurgical indus- 
tries. This, and the comparative cheapness of bituminous coal in the 
United States, also the low price commanded by the by-products until 
recently, will account for the laxity in conserving them. 

The annual output of tar from by-product coke-ovens in the United 
States is given in the following figures: 

1907 53,995,795 gallons 

1908 42,720,609 " 

1909 60,126,006 " 

1910 66,303,214 " 

1911 69,410,599 " 

1912 94,306,583 " 

1913 , 115,145,025 " 



234 ASPHALTS AND ALLIED SUBSTANCES 

1914 109,901,315 gallons 

1915 138,414,601 " 

1916 (estimated) 175,000,000 " 

1917 (estimated) 250,000,000 " 

The by-product coke-ovens now used in the United States include 
the Koppers, Semet-Solvay, United-Otto, and Otto-Hoffman types. 
The Simon-Carves coke-oven is used to a large extent abroad, in addi- 
tion to the foregoing.^ 

The temperature of coking varies between 1000 and 1200° C, and 
rarely above the latter inside the retort. The external temperature of 
the retort may run as high as 1700° C. According to White,^ the adapta- 
bility of coal for coking purposes is indicated with a fair degree of cer- 
tainty by the ratio of hydrogen to oxygen, together with the percentage 
of fixed carbon calculated on the moisture-free basis. Practically all 
coals with an H : ratio of 59 per cent or over, and less than 79 per cent 
of fixed carbon, possess that quality of fusion and swelling necessary 
to good coking. Bituminous coals with a ratio down to 55 will produce 
a more or kss satisfactory coke but coals with a ratio as low as 50 are 
unsuitable for coking purposes. 

The present systems of by-product oven construction resolve them- 
selves into two types depending upon whether the flue construction is 
horizontal or vertical. In either types the coking takes place in a narrow, 
retort-shaped chamber about 33 ft. long, from 17 to 22 in. wide, and 
about 6i ft. high. The width of the chamber averages 19 ft., which has 
proven suitable for completing the coking within 24 hours. The retort 
holds between 12 and 14 tons of coal. 

The ends of the retort are closed by means of iron doors lined with 
fire brick, which after being closed as tightly as possible are luted with 
clay to prevent the entrance of air. The coal is charged into the top 
of the oven, then pushed into place and leveled by mechanical devices. 
At the end of the coking, the doors are opened and the coke removed 
by a ram, the red-hot coke being immediately quenched with water. 

The number of ovens in a battery varies between 40 and 100, depend- 
ing upon the type of construction. The oven walls are constructed of 
fire brick containing about 95 per cent of silica, which on account of its 
very high fusing-point enables the ovens to be worked at high tem- 

»" Coke-oven Tars of the United States," by Provost Hubbard, Circular 97, Office of Public 
Roads, U. S. Dept. of Agr., Wash., D. C, Feb. 7, 1912; "By-products Recovered in the Manu- 
facture of Coke," by W. H. Childs, Amer. Iron and Steel Inst., N. Y., May 26, 1916. 

2"Tho EfTect of OKygen on Coal," Bulletin Np, 29, Bureau of Mines, Wash., D. C, 1916. 



COAL TAR AND COAL-TAR PITCH 



235 



peratures, and at the same time proves to be an excellent conductor of 
heat.i 

The coking in the by-product oven is in reality a destructive dis- 
tillation process, the heat required being supplied by burning a portion 
of the gases evolved. A large excess of gas is produced amounting to 
between 40 and 60 p-or cent of the total. 

The following is a brief description of the more important types of 
by-product coke-ovens used in the United States : 

Semet-Solvay Coke-oven. This is composed of a vertical retort heated on either 
side by sectional horizontal flues, in which the gases undergo combustion. The 
flues are constructed in small units which dovetail together, and constitute the 
lining of the retort, thus providing a rapid transmission of heat through the walls. 
The gases circulate from the top downward, as illustrated in Fig. 89. The gases 



^reheal-eof A 



Pre beared Air 



Preheafed Air from 
oiher Regenerator - 




Oas) 



From "Coal and Coke," by F. H. Wagner. 

Fig. 89. — Semet-Solvay Coke-oven. 



for combustion are introduced into the horizontal flues alternately from opposite 
sides, and at the same time mixed with air pre-heated by regenerators located in 
the base of the oven. The illustration shows a section through a heating flue, 
including one of the regenerators (the other not being shown). The products of 
combustion pass out through one of the regenerators into the stack. The other 
regenerator (not shown) is used for preheating the air to 1200-1400° F. After a 
time the paths of the gases are reversed, air being passed through the regenerator heated 
by the products of combustion, and vice-versa. Between 10,000 and 11,000 cu. ft. 
of gas are obtained per ton of coal, likewise 20 to 25 lb. of ammonium sulphate, 
and 9 to 10 gal. of tar. About half the gas is used for heating the retort, and 
the balance elsewhere for heating or illuminating purposes. 

Otto-Hoffman Coke-oven. This oven, as modified by Dr. F. Schneiwind, is 
illustrated in Fig. 90. The heating is eff"ected by vertical flues on either side of 
retorts (1) which are separated by hollow walls divided into 10 combustion chambers 

ij. W. Cobb, J. Soc. Chem. Ind., 36, 525, 1917. 



236 



ASPHALTS AND ALLIED SUBSTANCES 



(2), each containing 4 vertical flues (3). An air-chamber (4) runs lengthwise under- 
neath the floor of each retort passing through the openings (6) into the com- 
bustion flues (2). The air is pre-heated to 1800° F. by a pair of regenerators (7) 
operating alternately, and passed through the flue (5) into the air chamber (4). 
The gas for combustion is introduced through the pipe (10) into the combustion 
chamber (2). The products of combustion pass into the horizontal flue (9), then 
downward through the flues (not shown) corresponding to (3), but on the other 
side of the oven, through the regenerator (7), and thence into the chimney (not 




-Dischatgm^' 
Door 



From "Coal and Coke," by F. H. Wagner. 

Fig. 90. — Otto-Hoffman Coke-oven. 



shown). When the temperature of the regenerator (7) used for pre-heating the 
air falls to 1300* F., the passage of gases is reversed. 
The following yields per ton are recovered: 

Gas 15.0-16.0% (8,500-10,500 cu. ft.) 

Ammonium sulphate 0.8- 1.3% 

Tar 3.0- 6.4% 

Coke 70.0-75.0% 

Approximately 20 per cent of the nitrogen present in the coal is converted into 
ammonium compounds, part of which is found in the tar as pyridine, quinoline, 
etc. About half of the nitrogen remains in the coke, and may be regarded as lost. 

United-Otto Coke-oven. This is a modification of the Otto-Hoffman type, em- 
bodying the Hilgenstock principle of heating with vertical flues in conjunction with 
longitudinal regenerators (a) located underneath the retort (b), as illustrated in 
Fig. 91. The gas is introduced through one burner for each two vertical flues. 



COAL TAR AND COAL-TAR PITCH 



237 



The heating is made uniform by operating the burners alternately in sets of four 
on opposite sides of the retorts. Thus gas is introduced into the first four burners 
on the right-hand side of the retort, the second four on the left, the third four 
on the right, and so on. The products of combustion pass out at the side opposite 




From "Coal and Coke" by F. H. Wagner. 
Fig. 9L — LTnited-Otto Coke-oven. 



the burners, the respective paths being reversed from time to time. The yields 
from the United-Otto oven correspond very closely with those obtained from the 
Otto-Hoffman type. 

Koppers Coke-oven. This oven is illustrated in Fig. 92, the left-hand portion 
representing a section through the heating fines, and the right, a section through 
the retort. The oven is heated by a set of vertical flues in the side walls, the 




From "Coal and Coke," by F. H. Wagner. 

Fig. 92. — Koppers Coke-oven. 

heating gases and products of combustion respectively being passed through half 
the number alternately on each side and in opposite directions. The heating gas 
is admitted into a duct below the flues, and the air for combustion passes from 
the regenerator chambers directly into the vertical flues where it encounters the 
gas and undergoes combustion. The products of combustion travel upward in 



238 



ASPHALTS AND ALLIED SUBSTANCES 



one half of the oven and downwards in the other half, passing through the regen- 
erators and thence into the chimney. Each oven is provided with two regenerators. 
The average yield in per ton of coal is as follows: 

Gas 11,000 cu. ft. 

Ammonium sulphate 20 lb. 

Tar 13.4 gal. 

Coke 72% 

Production of Blast-furnace Coal Tar. Most blast-furnaces in the United States 
employ coke as fuel and a few use anthracite coal. Since all the volatile con- 
stituents have been removed from coke, and as anthracite coal contains only a 
very small percentage, no tar is obtained when either of these is used for smelting 
ores in blast-furnaces. In such cases the gases evolved are subjected to a puri- 
fication process merely to remove the entrained dust, before using them for heating 
purposes. 

Owing to the scarcity of anthracite and the high cost of bituminous coal in 
Europe and Great Britain, there is a tendency to reduce the operating expenses 

by using the latter in its raw state, without first 
converting it into coke. A non-coking bituminous 
coal must be selected for this purpose. In such 
cases the gases emanating from the blast-furnace 
carry a certain amount of tar, derived from the 
volatile constituents of the coal, which must be 
removed before they can be used for heating or 
power purposes. The gases also carry a com- 
paratively large amount of dust derived from the 
ores in the blast furnace, of which a good portion 
is removed by passing the hot gases through a 
device illustrated in Fig. 93, known as a "dry 
dust catcher." The gases entering the side of 
the catcher are given a rotary motion and their 
velocity reduced, whereupon they pass out at 
the top. This permits much of the dust to 
settle to the bottom, where it is emptied from 
time to time through a "spectacle valve." 

Other, and more complicated forms of dry 
dust catchers are also used for the purpose, but all depend upon three factors, viz.: 

(1) Changing the direction of the gas current. 

(2) Impinging the gas against soHd surfaces. 

(3) Reducing the velocity of the gases. 

Methods or Recovering Blast-furnace Coal-Tar. After being dry-cleaned, the gases 
are subjected to a wet-cleaning and cooling process by passing them through any 
of the types of coolers, scrubbers, or washers described on pages 174-179. The 
centrifugal washer is usually preferred as it operates rapidly and economically. 
A part of the tar condenses in the coolers, and the balance in the scrubbers and 
washers. It carries a large quantity of the wash water, which may be separated 
by any of the means described on p. 180. 

According to Lunge ^ approximately 7 gal. of blast-furnace tar and 29 lb. of 
ammonium sulphate are obtained from each ton of bituminous coal fed into the 

i"Coal Tar and Ammonia." New York, 1916. 




Fig. 93. 



-Blast- Furnace Dust 
Catcher. 



COAL TAR AND COAL-TAR PITCH 239 

blast-furnace. It appears that the iron ore and other minerals introduced with 
the coal influence the yield of tar. Thus the same bituminous coal gave the fol- 
lowing weights of tar per ton under varying conditions: 

Distilled alone in gas works 214 lb. of tar 

Distilled with English iron ore 66 lb. of tar 

Distilled with sand 170 lb. of tar 

The tar derived from blast-furnaces always carries a substantial proportion 
of mineral matter, which the dust catchers fail to remove, and which serves to 
distinguish it from the other varieties of coal tar. 

Production of Producer-gas Coal Tar. Unless the producer-gas plants 
are of a large capacity (above 4000 horse-power) it does not pay to 
recover the by-products. The smaller producers are designed to decom- 
pose the tar vapors and convert them into permanent gases, to avoid 
the expense of operating a tar-separating plant on one hand, or the 
trouble occasioned by the tar clogging the pipes and valves on the 
other. When anthracite coal or coke is used as fuel, no tarry vapors are 
produced. 

From the standpoint of tar recovery, producers may be divided into 
three classes, viz. : 

Type 1. Where the fuel travels in one direction, and the air and steam to- 
gether in the opposite direction. This is usually accomplished by introducing the 
fuel at the top, and both the steam and air at the bottom of the producer. 

Type 2. Where the fuel, air and steam all travel in the same direction. This 
may be accomplished by introducing all three either at the top, or at the bottom 
of the producer respectively. 

Type 3. Where part of the air travels in the same direction as the fuel, and 
the balance of the air together with all the steam in the opposite direction. In 
this type the exit for the vapors is in the centre of the producer, the fuel and 
part of the air being introduced at the top, and the steam with the balance of the 
air at the bottom. 

In all three types, four zones are distinguished, viz.: 

(a) The ash zone, which represents the fuel after all the carbonaceous material 
has been consumed. 

(6) The combustion zone, where the heat required for gasification is generated 
by the conversion of carbon into carbon dioxide. In this zone the highest tem- 
perature is attained (about 2100° F.). 

(c) The decomposition zone, where the inter-action takes place between the 
steam and incandescent carbon, yielding hydrogen and carbon monoxide, and where 
the carbon dioxide generated into the combustion zone combines with incandescent 
carbon and is converted into carbon monoxide. In this zone the temperature is 
in the neighborhood of 1800° F., and all the carbon is consumed. 

(d) The distillation zone, in which the raw fuel (e.g., the bituminous coal) 
undergoes partial distillation in consequence of the heat emanating from the de- 
composition zone (c). 



240 ASPHALTS AND ALLIED SUBSTANCES 

In type 1 the ash zone is at the bottom, and the combustion, decomposition 
and distillation zones superimposed one above the other, in the order mentioned. 
Since the vapors are drawn off at the top it follows that the tar does not suffer 
decomposition. 

In type 2 the distillation zone is at the top, the combustion zone directly beneath 
it, the decomposition zone still lower down, and the ash zone at the bottom of 
the producer. As the vapors are drawn from the bottom, the tarry matter gen- 
erated in the distillation zone is forced through the entire column of incandescent 
fuel, and as a result is partly "cracked" into permanent gases, and partly burned 
into carbon dioxide which in turn is converted into carbon monoxide. 

Type 3 is a combination of the other two, having two combustion zones, the 
upper part acting as a generator, and the lower as a producer. The distillation 
zone at the top is followed lower down by the first combustion zone, then the 
second combustion zone, and finally the ash zone at the bottom. The decompo- 
sition zone is in the centre, between the two combustion zones. In this type the 
tarry vapors evolved in the distillation zone are partly consumed by the incan- 
descent fuel in the combustion zone directly beneath it. This producer is also 
used for treating fuels containing a large percentage of volatile matter, including 
peat and lignite (p. 172). 

When ordinary bituminous coal is used as fuel, tarry matters are produced in 
Type 1, but not in Types 2 and 3, and the use of tar separators becomes super- 
fluous in the two last named. When peat (p. 201), lignite (p. 209), pyrobituminous 
shales (p. 216), and certain "highly volatile " bituminous coals are used as fuel, tar 
is generated in all three types, but to the greatest extent in Type 1, and must 
accordingly be separated from the gases. 

A representative Type 1 producer is illustrated in Fig. 94, known as a "suction 
gas producer," in which the vapors are drawn from the producer by means of a 
chimney or an exhaust fan, or else by the suction induced by the piston of a 
gas engine. The interior of the producer is maintained slightly below atmospheric 
pressure. It is constructed of double metal walls (C and C) between which a 
current of air absorbs the heat radiated through the inner shell and enters the 
bottom of the producer through the pipe (D). The troughs (E) between the walls 
carry water, which is converted into steam by the heat and mixes with the air 
passing through. The bottom of the producer is filled with water (G) in which 
the ashes accumulate. The mixture of air and steam enters through the pipe 
(H), and the combustion zone is protected with a fire-brick lining (B). The charging 
hopper (J) is provided with a cover (K) and a counterweighted valve (L), con- 
structed so that it is impossible to open either one, unless the other is closed. 
The gas is drawn from the producer through the pipe (M) and passed through 
the downcomer (P) leading into the scrubber (A^). The producer and scrubber are 
connected with the purge pipe {R) by the water-sealed three-way valve (0) in such 
a manner that the scrubber cannot be in communication with the purge pipe. 
The scrubber removes the tar and cools the gases, which are used for heating or 
power purposes. 

The tar is removed from the gases by one or more of the devices described on pp. 
174-179. About 90 lb. of water-free tar and 90 lb. of ammonium sulphate are recovered 
per ton of bituminous coal . The tar as shipped, after being allowed to settle, often 
contains up to 20 per cent water. 

Producers of Types 2 and 3 are illustrated in Figs. 95 and 96 respectively. 



COAL TAR AND COAL-TAR PITCH 



241 




'Disiilation 
Zone 






From "Gas Engines and Producers," by Marks. 

Fig. 94. — Fairbanks-Morse Suction Gas-Producer, Type L 




^OistilaHdnZone 



Combustion 
Zone 

IDecomposifion 
Zone 

Ash Zone 



Producer economUer 

From "Gas Engines and Producers," by Marks. 

Fig. 95. — Loomis-Pettibone Suction Gas-Producer, Type 2. 



242 



ASPHALTS AND ALLIED SUBSTANCES 



The Mond by-product gas producer is practically the only one used to any 
extent in the United States for recovering the tar and ammonium sulphate, which 
accounts for the fact that the former is not marketed in commercial quantities. 

Properties of Coal Tars. As stated previously, the expression '^ coal 
tar " is properly applied to tars derived directly from coal without 



OlSHLLATION ZONE 
COMBUSTION ZONE 



DECOMPOSITION ZON 



COMBUSTION ZONE 
ASH ZONE 




Fig. 96. — ^Westinghouse Gas-Producer, Type 3. 



admixture of petroleum. Coal tars differ in their physical properties 
depending upon their method of production. ^ The following types are 
distinguished : 

(1) Gas-works coal tar 

(a) From horizontal retorts 

(b) From inclined retorts 

(c) From vertical retorts 

(2) Coke-oven coal tar 

(3) Blast-furnace coal tar 

(4) Producer-gas coal tar 

* "Producer-gas Power-plant Development in Europe," by R. H. Fernald, Bulletin No. 4, 
Bureau of Mines, Wash., D. C, 1911. "Coal Gas Residuals," by F. H. Wagner, First Edition, 
New York, 1914. "Cleaning of Blast-furnace Gases," by F. H. Wagner, First Edition, New 
York, 1914. "Coal Tar Distillation," by Arthur R. Warnes, London, 1914. "American Coking 
Practice Up-to-date," by C. S. Lomax, Gas World, 63, 1620, 1915. "Gas Engines and Producers," 
by L. S. Marks and H. S. McDewell, Chicago, 1916. "Modern Gas Works Practice," by Alwyne 
Meade and Stanley H. Jones, London, 1916. "Coal and Coke," by F. H. Wagner, First Edition, 
New York, 1916. "Blast-furnace Construction in America," by J. E. Johnson, Jr., London, 1917; 
''Operation of Gas Works," by W. M. Russell, First Edition, New York, 1917. 



COAL TAR AND COAL-TAR PITCH 



243 



The Allowing figures will give a general idea of the physical properties 
of the four main classes of coal tar in their dehydrated state: 



(Test 1) Color in mass 

(Test 2a) Homogeneity to the eye 

at room temperature . 

(Test 26) Homogeneity under the 

microscope 

(Test 7) Sp.gr. at 77° F 

(Test 8) Viscosity 

(Test 13) Odor 

(Test 15) Fusing-point 

(Test 16a) Volatile matter 

(Test 17o) Flash-point 

(Test 19) Fixed carbon 

(Test 20) Distillation test (de- 
hydrated tar) : 
Light oils (up to 

235° C.) 

Middle, heavy and 
anthracene oils 

(235-355° C.) 

Soft pitch and loss 

(above 355° C.) . . 

(Test 21a) Soluble in carbon di- 

sulphide 

(Test 216) Non-mineral matter in- 
soluble (free carbon) . 

(Test 21c) Mineral matter 

(Test 22) Carbenes 

(Test 23) Solubility in 88° naphtha 
(Test 25) Water 

(Test 26) Carbon 

(Test 27) Hydrogen 

(Test 28) Sulphur 

(Test 29) Nitrogen 

(Test 30) Oxygen 

(Test 31) Free carbon 

(Test 32) Naphthalene 

(Test 33) Paraffine 

(Test 35) Sulphonation residue. . 

(Test 37) Saponifiable 

(Test 41) Diazo reaction 

(Test 42) Anthraquinone reaction 



Gas-works 
Coal Tar. 



Black 

Fine particles 

Lumpy 

1.15-1.30 

Variable 

Characteristic 

Below 25° F. 

25-50% 

Low 
15-40% 



2-3^% 

15-30% 

60-85% 

60-95% 

5-40% 
0-1% 
0-2% 
20-40% 
Trace 



Coke-oven 
Coal Tar. 



Black 

Fine particles 

Lumpy 

1.10-1.30 

Low 

Characteristic 

Below 25° F. 

30-60% 

Low 
15-40% 



i-3|% 

20-35% 

55-75% 

80-97% 

3-20% 
0-1% 
0-2% 
20-40% 
Trace 



Blast-furnace 
Coal Tar. 



Black 

Fine particles 

Lumpy 

1.15-1.30 

Low 

Characteristic 

Below 25° F. 

30-60% 

Low 
5-25% 



Producer-gas 
Cof:l Tar. 



65-80% 

10-25% 
10-15% 

0-2% 
15-35% 

Trace 



88 -93% 
4 -7% 
0.1-0.9% 
1.0-1.5% 
1.0-3.0% 
(See Test 216) 
3 -10% 
0% 



IMack 

Fine particles 

Lumpy 

1.15-1.30 

Low 

Characteristic 

Below 25° F. 

30-60% 

Low 
10-35% 



75-90% 

10-25% 
0-2% 
0-2% 

20-40% 
Trace 




244 ASPHALTS AND ALLIED SUBSTANCES 

J. M. Weiss furnishes the following figures representative of typical coal tars.^ 





Gas-wokks Coal Tars. 


Coke-oven Coal, Tars. 




Hori- 
zontal 
Retorts. 


Inclined 
Retorts. 


Vertical 
Retorts. 


United 
Otto. 


Semet- 
Solvay. 


Koppers. 


(Test 7) Specific gravity at 60° F 

(Test 8a) Specific Engler viscosity at 

212° F 

(Test 20a) Distillation test (dehydrated 
tar): 
Distillate by volume to soft 
pitch of 60° C. fusing-point 


1.266 
21.8 

13.2% 

86.8% 

1.5932 

28.9% 

0.4% 

14.0% 


1.238 
14.9 

14.3% 

85.7% 

1 . 5807 
14.9% 

2.4% 
21.0% 


1.153 
2.1 

28.8% 

71.2% 

1.5755 

2.1% 

4.3% 

29.0% 


1.207 
3.4 

21.2% 

78.8% 

1.5987 
3.4% 
0.0% 
12.0% 


1.188 
3.0 

21.8% 

78.2% 

1.6122 
3.0% 
0.0% 
4.0% 


1.186 
2.1 

35.3% 


Residue by volume (soit pitch 
of 60° C. fusing-point — 


64.7% 


Refraction index of distillate 
at 60° C 


1.6139 


(Test 31) Free carbon (insoluble in benzol) 
(Test 35) Sulphonation residue 


2.1% 
0.0% 


(Test 37e) Tar acids in above distillate .... 


0.0% 



Weiss reports ^ that gas-works coal tar has a coefficient of expansion for 1° F. 
(length = 1) of 0.00027-0.00032 and coke-oven coal tar 0.00030-0.00034. 

Weiss ^ also reports the following relationship between the specific gravity and 
the free carbon in gas-house and coke-oven coal tars respectively. 





Specific Gravity 
at 60° F. 


Free Carbon 
per cent. 


Gas-house coal tar. . 
Coke-oven coal tar. . 


1.203-1.296 

1.178-1.258 


16.67-33.17 
4.04-19.06 



The differences between the tars produced at the present time may be 
roughly expressed as follows (W. H. Childs, loc. cit.): the gas-works 
coal tar derived from the old-fashioned horizontal retort is the heaviest, 
most viscous, containing a lower percentage of oils, the most pitch, and 
also the highest percentage of free carbon. Coke-oven coal tar occupies 
an intermediate position, being lighter, containing more oils, less pitch 
and less free carbon than the preceding. Gas-works coal tar derived 
from vertical retorts is lighter, less viscous, contains more oils, less pitch 

»7. Ind. Eng. Chem., 8, 842, 1916. 
«J. Franklin Inst., 172, 277, 1911. 
» Ibid. 



COAL TAR AND COAL-TAR PITCH 



245 



and less free carbon than coke-oven coal tar. The following table con- 
tains the analyses of tars derived from gas-works and coke-ovens : 





Gas-works 


Coal Tar^. 


Coke-oven 










Coal Tars. 




Hori- 


Hori- 














zontal 


zontal 


Inclined 


Vertical 


Type 


Type 


Type 




Retorts 


Retorts 


Retorts. 


Retorts. 


A. 


B. 


C. 




(old). 


(new). 












(Test 7) Specific gravity at 60° F 


1.254 


1.218 


1.198 


1.154 


1.178 


1.173 


1.187 


(Test 8a) Engler viscosity at 212° F. 
















(seconds for 100 c.c.) . . . 


273 


103 


89 


30 


76 


30 


37 


(Test 20a) Distillation test (dehydrated 
















tar): 
















Light oil (to 400° F 


2.0% 


3.3% 


4.1% 


3.7% 


5.3% 


1.8% 


1.4% 


Middle and creosote oils. . . 


18.7% 


21.1% 


22.1% 


30.2 % 


20.8% 


35.0% 


24.0% 


Soft pitch (including loss) . . 


79.3% 


75.6% 


73.8% 


61.2% 


73.9% 


63.2% 


74.6% 


(Test 25)* Water 


2.8% 


5.2% 


3.3% 


3.6% 


1.0% 


1.3% 


2.3% 


(Test 31) Free carbon (insoluble in ben- 








zol) 


29.8% 


21.6% 


19.9% 


3.7% 


7.6% 


4.3% 
1.1% 


10.4% 
0.34 


(Test 37e) Tar acids (phenols, cresols, etc) 


1.6% 


2.9% 


5.2% 


7.2% 


5.0% 



Coal tars may be recognized by the odor which is characteristic, by their high 
specific gravity, large percentage of free carbon (non-mineral matter insoluble in 
carbon disulphide), absence of paraffine, small percentage of sulphonation residue, 
small percentage of sulphur (0.10-0.90) and by the presence of phenols (diazo 
reaction), anthracene (anthraquinone reaction) and naphthalene.^ 

Refining of Coal Tar.^ Table XIX shows the approximate composi- 
tion of coal tar and the various products derived therefrom. 

According to G. Kramer,^ an average sample of European coal tar contained 
the following: 

Benzol and its homologues 2 . 50% 

Phenol and its homologues 2 . 00% 

Pyridine and quinoline bases . 25% 

Naphthalene and acenaphthene 6 . 00% 

Heavy oil 20 . 00% 

Anthracene and phenanthrene 2 . 00% 

Pitch 62.00% 

Ammoniacal liquor 4 . 00% 

Gases and loss 1 . 25% 

Total 100.00% 

1 " Naphthalene in Road Tars," by Hubbaru and Draper, Circular No. 96, Office of Public 
Roads, U. S. Dept. of Agri., Wash. D. C, Nov., 1911. 

2 "Coal Tar Light Oil in the United States; the Manufacture, Nature, and Uses of Products 
Derived Therefrom," by J. M, Weiss, 8th Intern. Cong. Applied Chem. 10, 287, 1912; "Coal- 
tar Products," by Horace C. Porter and C. G. Storm, Circular 89, Bureau of Mines, Dept. of 
Interior, Wash., D. C, 1916; "Tar and Its By-products," by S. R. Church, Gas Age, 31, 497, 
19-13; "Tar Distillation In the United States, General Development and Recent Progress," by 
E^|P. Perry, 8th Intern. Cong. Applied Chem., 10, 233, 1912, also J. Ind. Eng. Chem., 6, 151, 
1943. 

"^"*'J. Gasbel. 34, 225, 1891. 



246: ASPHALTS AND ALLIED SUBSTANCES 

Cod tar is transported from the gas-works or coke-ovens in cylindrical 
steel tank-cars 7 to 8 ft. in diameter and 28 to 30 ft. long holding about 
10,000 gal., provided with a dome on top and heating coils inside for 
the introduction of steam in cold weather to reduce the fluidity. It is 
transported by water in tank-vessels constructed similarly to those used for 
petroleum, holding up to 300,000 gal. At the distilling plant the tar 
is generally stored in covered vertical cylindrical steel tanks larger in 
diameter than height, having a capacity up to 2 million gallons. A 
certain amount of water separates out during storage which is tapped 
through pet-cocks in the side. Less often the tar is stored in rectan- 
gular reinforced concrete tanks built underground. 

A preliminary insight may be obtained regarding the constitution 
and probable value of coal tar by subjecting it to a laboratory distillation 
test (see test 20, p. 521), according to which it is separated into five frac- 
tions and a residue of pitch. These fractions are distinguished as follows: 

American Practice. European Practice. 

Water, etc Up to 110° C. Up to 110° C. 

Light oil 110-170° C. 110-170° C. 

Middle oil 170-235° C. 170-230° C. 

Heavy oil \ f 230-270° C. 

Anthracene oil. j ^^5 d55 (.. ^ 270-350° C. 

Residue (coal-tar pitch) Above 355° C. Above 350° C. 

This test is often used by the stillman as a basis for arriving at the 
volume of the respective fractions to be separated in the works dis- 
tillation. 

The crude tar is first dehydrated by one of the methods described 
on p. 180. The method generally used in the United States consists 
in heating the tar in thin layers under partial vacuum. The tar is allowed 
to flow continuously over heated steam plates in a closed cylindrical 
vessel as described in method 5, p. 182, and which reduces the water to 
less than 0.5 per cent. From the dehydrator, the hot tar is pumped 
directly into the still. 

The form of still used in the United States consists of a horizontal 
cylinder with convex ends heated directly either by coal or gas, con- 
structed to hold as much as 75 tons of tar. A typical still is illustrated 
in Fig. 97. The tar enters through a pipe into the top of the still, 
and the vapors are drawn off through another pipe of large diameter 
attached directly to the top of the still, at the centre. The stills are 
not usually provided with domes as is the case with petroleum stills. 
The outlet pipe for the pitch is located at the bottom, together with 
inlet pipes for steam or air agitation. Sometimes vacuum is used to 
reduce the time of distillation. The stills are mounted on a brick 



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' TABLE XIX 

Diagram OFTHE Prodvcts derived from coal and some of ther vses 



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To /are />a(/f ^<;<5 



COAL TAR AND COAL-TAR PITCH 



247 




Courtesy of The Barrett Company. 

Fig. 97.— Horizontal Still for Refining Coal Tar. 

setting provided with a fire arch to insure uniform heating, and prolong 

the life of the bottom. The process is an intermittent one. After 

the tar has been distilled to the 

desired fusing-point or consistency 

the residue of pitch is discharged 

by gravity, pumping or blowing 

out with air. 

In Europe, tar stills are con- 
structed in the form of a '^ pot " 
or vertical still having a concave 
bottom, as illustrated in Fig. 98, 
where 1 represents the manhole; 
2, safety-valve connection; 3, swan 
neck; 4, swan neck stool; 5, dipp'vng 
tap; 6, steam inlet; 7, steam pipe; 
8, tar inlet; 11, tar outlet. The 
concave bottom is claimed to have 
the advantages of providing a larger 
heating surface, also to assist in 
draining off the pitch and to accom- 
modate the expansion and contrac- 




From "Coal Tar Distillation," by A. R. Warnes. 

Fig. 98.— Vertical Still for Refining 
Coal Tar. 



248 ASPHALTS AND ALLIED SUBSTANCES 

tion of the metal plates without setting up dangerous strains. Steam 
is introduced during the process of distillation through a perforated pipe 
(9-10) at the bottom and servey to carry off the vapors more rapidly, 
also reduce the time of distillation. English stills hold 20 to 40 tons of 
tar, and are mounted on suitable brick settings adapted for direct 
heating with coal or producer gas. 

The vapors leave the still through a large pipe connected with the 
condenser coils immersed in water in a rectangular tank. These coils 
are constructed of pipes ranging from 6 in. down to 3 in. in diameter. 
The distillate is run into small measuring tanks which in turn empy 
into large storage tanks. Each fraction is caught separately, four fractions 
all told being recovered, viz.: light oil or crude naphtha, middle or car- 
bolic oil, heavy or creosote oil and anthracene oil. 

On starting the distillation, the light oil or crude naphtha boils over, 
comprising the entire distillate lighter than water. When the vapor 
temperature reaches about 200° C. the receiver is changed, and the next 
runnings constituting the middle or carbolic oil are caught separately. The 
light oil fraction varies from less than 1 per cent to 3 or 4 per cent. It 
is redistilled and fractioned into solvent naphtha and heavy naphtha, 
also small amounts of crude benzol, toluol, phenol and cresols. 

The middle or carbolic oil comes over next, amounting to 5 to 15 
per cent. As the temperature increases, naphthalene crystallizes out in 
the distillate, and to prevent it choking the condensing coils, the cooling 
water is shut off. It is cut at such a point to include most of the tar 
acids and naphthalene, and is cooled to remove the naphthalene and 
sold as a disinfectant. The tar acids may also be extracted with caustic 
soda and liberated by sulphuric acid or carbon dioxide. The phenol con- 
tent of tar seldom exceeds J per cent, and naphthalene recovered from this 
and the succeeding fractions will range from 5 to 7 per cent. 

As the temperature increases, the heavy or dead or creosote oil boils 
over. This may represent the entire fraction between the middle oil 
and the end of the distillation, in which event it will constitute 15 to 35 
per cent of the tar, or it may be cut sooner and the anthracene oil caught 
separately. In either event the distillation is assisted by introducing 
live steam. The distillate is cooled to remove any naphthalene, and 
the cresols extracted in the same manner as phenol. The anthracene oil 
is treated to separate pure anthracene, amounting to 0.2 per cent of the 
tar, which constitutes the source of alizarin used in manufacturing coal- 
tar dyes. 

When the distillation is completed the pitch remains as a residue 
in the still, amounting to 50 to 80 per cent of the tar, and varying from a 



COAL TAR AND COAL-TAR PITCH 



249 



viscous to a hard and brittle product, depending upon the quantity of 
distillate removed. It is allowed to run or pumped into a cooler consist- 
ing of a rectangular (8X8X8 ft.) or cyhndrical vessel, and allowed to 
remain until the temperature falls to 250 to 300° F., whereupon it is run 
into barrels. Each still is provided with two or more coolers, so as not 
to delay removing the pitch. 

The stillman is guided in separating the various fractions by the 
volumes recovered, calculated from the percentages reported by the 
laboratory distillation test. 

Various types of stills adapted to the continuous distillation of tar, 
have recently attracted attention. Among them the Kubierschky system ^ 
is claimed to give good results. The tar is sprayed into the still, and at 
the same time a current of superheated steam introduced from below 
comes in direct contact with the tar. The distillation progresses in stages 
in a series of connecting chambers, from each of which a different fraction 
is recovered, the pitch residue being drawn off at the bottom. It is 
claimed that it is unnecessary to first dehydrate the tar, also that the 
steam consumption is comparatively small. 

One of the most promising systems, from a scientific standpoint, for separating 
coal tar into its various fractions, was devised by Walther Feld,^ by which the 




Fig. 99. — Feld System for Fractioning Coal Tar. 

tar vapors are fractioned directly as they come from the gas-retorts or coke-ovens. 
The principle involved is exactly the reverse of the foregoing methods. In the 
Feld system, the hot tar vapors are separated into various fractions by a system 
of selective cooling, whereas in the other methods the coal tar is progressively 
heated to successively increasing temperature and each fraction condensed as it 
vaporizes. One of the main advantages claimed for the Feld system is the saving 
of fuel, since it utilizes the heat extant in the hot tar vapors and obviates reheating. 
A rough outline of the Feld condensing system is illustrated in Fig. 99. The 
hot vapors coming from the retorts of ovens are passed through a series of Feld 
centrifugal scrubbers (see p. 177) in each one of which the washing liquid constitutes 



ij. Gas Lighting, 130, 448, 1915. 

2 "Coal Gas Residuals," by F. H. Wagner. N. Y. 



1914. 



250 



ASPHALTS AND ALLIED SUBSTANCES 



a portion of the condensate recovered in the next succeeding washer, and has 
therefore, a lower boihng-point than the fraction to be separated. Altogether 11 
centrifugal washers are proposed. The vapors coming from the hydraulic main at 
a temperature of 200° C. are introduced into washer No. 1, and washed with a 
carefully regulated quantity of "heavy oils" obtained from washer No. 2 (pre- 
viously brought to a temperature of 160° C.) to reduce the temperature of the 
vapors in washer No. 1 to 160° C. This effects a separation of the constituents 
boiling above 320-350° C. (i.e., the pitch) from those of lower boiling=points ("dew 
points"). The reduction in temperature of the hot vapors may be accounted for 
partly by the low temperature of the circulating liquid and partly because of its 
vaporization and consequent absorption of heat. 

The vapors now at a temperature of 160° C. are passed into washer No. 2, . 
through which sufficient "middle oils" obtained from washer No. 3 (at a tem- 
perature of 80° C.) are circulated to reduce the temperature of the vapors in washer 
No. 2 to 80° C, and thus bring about a condensation of the constituents boiling 
between 230 and 320° C, known as the "heavy oils." 

Similarly, washer No. 3 removes the middle oils by circulating a quantity of 
the oil condensed in washer No. 4 (at a temperature of 60° C), which serves 
to reduce the temperature of the vapors to 60° C. 

A detailed plan of operation is indicated in Table XX: 

TABLE XX 



Washer 

No. 


Circulating Liquid. 


Temp, of 

Circulating 

Liquid, 

Deg. C. 


Temperature 
of Vapors 
Reduced, 
Deg. C. 


Constituents Separated 
from the Vapors. 


Boiling- 

Point of 

Condensate 

Deg. C. 


1 


Warmed heavy oils from 

No. 2. 
Warmed middle oils from 

No. 3. 
Warmed oils from No. 4. 
Water 


160 

80 

60 
40 

40 

38 

36 

34 

18 


From To 
200 160 

160 80 

80 60 
60 40 

40 

40 38 

38 36 

36 34 
34 18 

18 

18 


Pitch 




2 

3 
4 


Heavy oil (anthracene 

oil). 
Middle oil (creosote oil) 
Oils and water 

Light oil 


320-350 
230-320 

170-230 


5 


Cooled heavy oils from 

No. 2. 
Water 


Below 170 


6 


Ammonia and hydrogen 

sulphide 
Ammonia and hydrogen 

sulphide 
Cyanogen 
Naphthalene 

Benzol 

Benzol 


■ 


7 


Water 




8 


Water 




9 


Water 




10 


Cooled light oils from 

No. 5. 
Benzol from No. 10 


18 
18 




11 









It is claimed that the vapors thus treated produce a gas of greater illuminating 
power than one which has been purified in the usual manner, also that the method 
is adpated equally well for treating gas-house or coke-oven products. It has also 
been used apparently with some success abroad for the fractional separation of 
the tarry vapors obtained on destructively distilling Bohemian lignite (browncoal) 
but has not come into use in this country. The yield of pitch from the Feld 



COAL TAR AND COAL-TAR PITCH 251 

process is lower than that obtained from the ordinary method, and the yield of 
the more valuable oils correspondingly increased. In one case a bituminous coal 
yielding 35 per cent of pitch by the ordinary method produced 7^ to 12 per cent 
by the Feld process. 

Properties of Coal-tar Pitches. The extent to which the distillation 
or condensation is continued in any of the foregoing methods deter- 
mines the character and nature of the residue. If the light oil and part 
of the middle oil are distilled off, there remains a product varying in 
consistency from a thin to a more or less viscous liquid, known as 
" refined coal tar " or " distilled coal tar." Its physical properties are 
intermediate between the crude tars and the pitches. These tars are 
used for road binders (see p. 357) or for saturating purposes (see p. 395) 
Coal tar suitable for saturating roofing felt is usually prepared by dis- 
tilling a charge until the residue tests between 80 and 120 at 40° F. by 
the Shutte penetrometer (test Se). If the distillation is continued to 
the desired point, then the residue is known as '' straight-run coal-tar 
pitch." On the other hand, if the distillation is carried to a point 
where the residue is harder and more infusible than desired, and is there- 
upon fluxed to the desired consistency and fusing-point either with cer- 
tain fractions of the distillate or a flux of foreign origin — usually of little 
value commercially — or with other tars, then the pitch is known as 
"cut-back coal-tar pitch." 

Prepared tar suitable for road treatment may be manufactured by 
selecting suitable crude or dehydrated tars, combining them in the still 
and running to the proper consistency. Another plan consists in run- 
ning a single tar to pitch, adding a suitable quantity of dehydrated or 
distilled tar, and agitating with air introduced through a perforated pipe. 

Coal-tar pitches have been arbitrarily classified as follows: "soft 
pitch," having a fusing-point between 90 and 120° F. (cube method) 
used principally for road binders and sometimes for waterproofing work 
(see p. 442); ''medium pitch," having a fusing-point between 120 and 
160° F. (cube method), used for constructing '' pitch and felt roofs " 
(see p. 444), for waterproofing work (see p. 443), for filling joints in 
stone pavements (see p. 382) and for manufacturing paints (see p. 462) ; 
" hard pitch," having a fusing-point between 160 and 210° F.(cube method), 
used principally for briquetting purposes (see p. 454) ; " very hard pitch " 
having a fusing-point above 210° F. and rarely exceeding 266° F.,^ used 
as binders for sand cores in forming castings of iron and steel, also for 
manufacturing electric light carbons, battery carbons, plastic compositions 
for insulating purposes and black " clay pigeons " for target shooting. 

' It is possible to prepare coal-tar pitches fusing as high as 345° F., but these are scarcely ever 
encountered. 



252 



ASPHALTS AND ALLIED SUBSTANCES 



J. M. Weiss reports ^ that the specific gravity of coal-tar pitch varies from 
1.200-1.290 at a fusing-point of 100° F. (cube method) to 1.250-1.350 at a 
fusing-point of 190-200° F. (cube method). 

Coal-tar pitches show the following ranges: 



(Test 1) Color in mass 

(Test 2a) Homogeneity at 77° F 

(Test 2a) Homogeneity under microscope. 

(Test 26) Homogeneity when melted 

(Test 3) Appearance surface on aging . , 

(Test 4) Fracture 

(Test 5) Lustre 

(Test 6) Streak 

(Test 7) Sp. gr. at 77° F 

(Test 9c) Hardness at 77° F 

(Test 9d) Susceptibility factor 

(Test 106) Ductility at 77° F 

(Test 13) Odor on heating 

(Test 14a) Behavior on heating 

(Test 15a) Fusing-point (K. and S. method) 

(Test 156) Fusing-point (Cube method).. . . 

(Test 16) Volatile matter, 500° F., 4 hrs.. 

(Test 17a) Flash-point 

(Test 18) Burning-point 

(Test 19) Fixed carbon 

(Test 21a) Soluble in carbon disulphide. . . . 

(Test 216) Non-mineral matter insoluble. . . 

(Test 21c) Mineral matter 

(Test 22) Carbenes 

(Test 23) Soluble in 88° naphtha 

(Test 24) Soluble in other solvents 



(Test 26) Carbon* 

(Test 27) Hydrogen 

(Test 28) Sulphur 

(Test 29) Nitrogen 

(Test 30) Oxygen 

(Test 32) Naphthalene 

(Test 33) ParafEne 

(Test 35) Sulphonation residue. . . 

(Test 37) Saponifiable constituents 

(Test 40) Glycerol 

(Test 41) Diazo reaction 

(Test 42) Anthraquinone reaction. . 



Gas-works 

Coal-tar 

Pitch. 



Coke-oven 

Coal-tar 

Pitch. 



Blast-furnace 

Coal-tar 

Pitch. 



Black Black Black Black 

Variable Variable Variable Variable 

Carbon vis- Carbon vis- Carbon vis- Carbon vis- 
ible ible ible ible 

Uniform Uniform Uniform Uniform 

Unchanged Unchanged Unchanged Unchanged 

Conchoidal Conchoidal Conchoidal Conchoidal 

Variable Variable Variable Variable 

Black Black Black Black 

1.15-1.40 1.20-1.35 1.20-1.30 1.20-1.35 
10-100 10-100 10-100 10-100 

>100 >100 >100 >100 

Variable Variable Variable Variable 
Penetrating odor charactelristic of all coal-tar pitches. 
Passes rapidly from the soljd into the liquid state. 



Producer-gas 

Coal-tar 

Pitch. 



80-300° F. 


80-300° F. 


80-300° F. 


80-300° F. 


90-345° F. 


90-345° F. 


90-345° F. 


90-345° F. 


3-20% 


3-20% 


3-20% 


3-20% 


250-450° F. 


250-450° F. 


250-450° F. 


250-450° F. 


300-500° F. 


300-500° F. 


300-500° F. 


300-500° F. 


30-45% 


20-45% 


10-30% 


20-45% 


55-90% 


60-85% 


50-75% 


60-85% 


10-45% 


15-40% 


15-35% 


15-40% 


0-1% 


0-1% 


10-20% 


0-2% 


2-10% 


2-10% 


2-10% 


2-10% 


10-30% 


10-30% 


5-25% 


10-30% 


Coal-tar pitcl 


les are largely soluble in carbon disulphide, 


benzol, coal 


-tar distillates, carbon tetrach 


loride, chloro- 


form, and 


glacial acetic acid. They are only partly 


soluble in \ 


3etroleum distillates, turpen 


tine, grain or 


wood alcohc 


1. 






90 -95% 






3 - 5% 






0.5- 1.0% 






0.2- 1.2% 






Trace- 2.0% 






Trace- 2.5% 






0.0% 




0-5% 


0-5% 


5-20% 


0-5% 


Tr. -1% 


Tr.-1% 


Tr.-1% 


Tr.-1% 




0.0% 
Yes 






Ye 


3 





* For the ultimate analysis of coal-tar pitches, refer to Donath and Asriel, Chem. Rev. Fett' 
Harz-Ind., 10, 64, 1903; also C. E. Downs, J. Ind. Eng. Chem., 6, 206, 1914. 



iJ. Ind. Eng. Chem., 8, 841, 1916. 



COAL TAR AND COAL-TAR PITCH 



253 



Church and Weiss examined representative specimens of coal-tar pitches/ with 
the following results, in which A represents gas-works coal-tar pitch obtained from 
horizontal retorts, B gas-works coal-tar pitch from inclined retorts, C gas-works 
coal-tar pitch from vertical retorts, D Otto-Hoffman coke-oven coal-tar pitch, E 
Semet-Solvey coke-oven coal-tar pitch, and F Scotch blast-furnace coal-tar pitch: 



(Test 7) 
(Test 96) 



(Test 15c) 

(Test 19) 
(Test 21o) 
(Test 216) 

(Test 2ic) 
(Test 22) 
(Test 31) 



Sp. gr. at 60° F.. . 

Hardness at 115° F. (50 
g. for 5 s.) 

Hardness at 77° F. (100 
g. for 5 s) 

Hardness at 12° F. (200 
g. for 60 s.) 

Fusing-point (cube 
method) 

Fixed carbon 

Sol. in carbon disulphide 

Non-mineral matter in- 
soluble 

Mineral matter 

Carbenes 

Insoluble in benzol and 
toluol (free carbon) . . . 



A 


B 


C 


D 


E 


1.30 


1.28 


1.19 


1.25 


1.25 


Too soft 


Too soft 


Too soft 


Too soft 


Too soft 


39 


40 


44 


41 


39 


2 


2 


2 


3 


2 


125° F. 


123° F. 


125° F. 


126° F. 


126° F. 


41.5% 


37.0% 


16.3% 


28.5% 


28.2% 


64.9% 


67.8% 


89.5% 


79.9% 


82.5% 


34.9% 


32.0% 


10.3% 


19.7% 


17.4% 


0.2% 


0.2% 


0.2% 


0.4%, 


0.1% 


3. 5% 


2.8% 


5.3% 


7.4% 


5.9% 


34.9% 


30.8% 


8.0% 


21.1% 


18.3% 



1.23 
324 



41 



8 



135° F. 
14.4% 
58.2% 

30.0% 
11.8% 

2.6%: 

28.4% 



A sample representing a well-advertised brand of straight-run gas-works coal-tar 
pitch was tested by the author with the following results: 

(Test 7) Specific gravity at 77° F 1 . 25 

(Test 9a) Consistency at 115° F 5.0 

Consistency at 77° F 24 . 7 

Consistency at 32° F > 150 

(Test 9d^ Susceptibility factor > 100 

(Test 106) Ductility at 115° F 35 

Ductility at 77° F 75 . 5 

(Test 9d) Ductility at 32° F 

(Test 11) Tensile strength at 115° F 0.15 

Tensile strength at 77° F 4 . 65 

Tensile strength at 32° F 8.5 

(Test 15a) Fu.sing-point (K. and S. method) 122° F, 

(Test 16) Volatile matter, 500° F. in 4 hrs 8.2% 

(Test 17a) Flash-point 360° F. 

The consistency, tensile strength (multiplied by 10) and ductility curves are 
shown in Fig. 100. 

Coal-tar pitches are characterized as follows:^ 

(1) Jet black streak on porcelain. 

(2) Carbonaceous matter clearly visible under microscope. 

(3) Comparatively high specific gravity. 

^ Proc. Am. Soc. Testing Materials, 15, 274, Pait II, 1915. 

»"Chemische Zusammensetzung und Untersuchung der natiirlichen und ktinstlichen Asphalte," 
J. IMarcusson, Chem. Rev. Fett-Harz-IruL, 19, 166, 1912; "Nachweis von Naturasphalt und Erdolpech 
in Ruckstanden der Steinkohlenteerdestillation," F. Schwartz, Chem. Rev. Fett-Harz-Ind., 20, 28, 1913. 



254 



ASPHALTS AND ALLIED SUBSTANCES 



(4) High susceptibility factor. This means that they are largely 
influenced by changes in temperature, becoming brittle in winter, and 
softening under extreme summer heat. 

(5) High ductility when tested at temperatures ranging between the 
solid and fluid states. 

(6) Characteristic odor on heating. 

(7) Pass rapidly from the solid to the fluid state. 

(8) Comparatively high percentage of volatile constituents when 
heated at 500° F. for 4 hours. 









32" 








7- 


r' 






115* 












140 
130 








\ 


/" 


N 
















LEGEND 

— '— Hordne55 








\ 


/ 

1 


\ 
\ 
\ 






















f 


\ 
















Tensile 


no 

110 
100 
90 
80 
70 

eo 

50 
40 
30 
20 
10 





i 


dtren^thUlo) 

Ductility 

© Fusing Pbint 








/ 

; 
/ 






\ 
\ 




















/ 
; 
/ 


\ 




\ 
\ 




















/ 
\ 


\ 




\ 
\ 
\ 






























l83 


\ 




\ 
\ 
\ 




/ 


""n 




















^^. 


y 






\ 




\ / 


75.5 




\ 
\ 




















" 






\ 










\ 

\ 


























\ 


V 


( 






\ 

\ 




























\ 


1 
/ 


46.5 






\ 


























\ 


J 


\ 
\ 






I 


[35 






















/ 


N 


\ 








X 


\ 






















/ 




X: 


s 








\ 


\ 














p 




^' 










^. 


r^ 







^_ 


^-. 


-^ 




I 


z 


3( 


} A 


5 


6 


7 





so 9 


IC 


X) 1 





1 


?0L 


50 1-^ 


10 \l 


le 


jO 



Temperature, Degrees Fahrenheit. 
Fig. 100. — Chart of Physical Characteristics of Coal-tar Pitch. 



(9) Comparatively high percentage of fixed carbon. 

(10) Comparatively high percentage of non-mineral matter insoluble 
in carbon disulphide C' free carbon"). 

(11) Comparative insolubility in petroleum naphtha. 

(12) Comparatively small percentage of sulphur. 

(13) Presence of naphthalene. 

(14) Absence of paraffine. 

(15) Comparatively small percentage of sulphonation residue. 

(16) Give both the diazo and anthraquinone reactions. 



COAL TAR AND COAL-TAR PITCH 



255 



Coal-tar pitches are remarkably resistant to the disintegrative action 
of water, and are therefore well adapted for sub-soil waterproofing. They 
are more weather resistant than wood-tar pitch, rosin pitch, lignite-tar 
pitch, shale-tar pitch and bone-tar pitch, but are inferior to caiefully 
prepared residual asphalts obtained from petroleum, blown petroleum 
asphalts, wurtzilite asphalt, fatty-acid pitches and pure native asphalts 
containing approximately the same percentage of volatile matter (see 
p. 341). 

Attempts have been made to blow coal-tar pitches by the same process used 
for treating petroleum asphalts (p. 287). Samples tested by the author showed 
a slight lowering of specific gravity, a decrease in the hardness for a given fusing- 
point, a decrease in the susceptibility factor (i.e., the material was less affected 
by changes in temperature) and no appreciable change in the ductility. Blown 
coal-tar pitches have not been marketed in commercial quantities, nevertheless they 
warrant further development. 

Specimens of blown coal-tar pitches examined by the writer showed the following 
results : 



7) 
9c) 



9d) 
10b) 



Specific gravity at 77° F 

Consistency at 115° F , 

Consistency at 77° F 

Consistency at 32° F 

Susceptibility factor 

Ductility at 115° F 

Ductility at 77'' F 

Ductility at 32° F 

Tensile strength at 115° F 

Tensile strength at 77' F 

Tensile strength at 32° F 

(Test 15a) Fusing-point (K. and S. method) 



(Test 
(Test 



(Test 
(Test 



(Test 11) 



1.184 
1.08 
10.0 
>100 
> 89 
51 
100 
0.0 
0.1 
2.1 
5.5 
112° F. 



1.194 
4.31 
57.5 
>100 
> 70 
100 
0.25 
0.0 
0.9 
8.0 
6.5 
136° F. 



1.202 

5.94 
66.9 
100 
66 
92 

0.0 

0.0 

1.4 

8.8 

7.5 
141° F. 



CHAPTER XVIII 
WATER-GAS AND OIL-GAS TARS AND PITCHES 



Water-gas tar, oil-gas tar and their corresponding pitches are not 
classified with '' coal tar " and " coal-tar pitch/' as they are inter- 
mediate in their properties between the latter and petroleum asphalts on 
account of the petroleum products used in their manufacture. They are 
accordingly included in a separate chapter. 

Water-gas Tar. The mechanism of this process has already been briefly 
described on page 173. A modern water-gas plant having a capacit}^ of 
IJ to 3 milHon cubic feet of gas per day is illustrated in Fig. 101. This 



Sfear. 



Water 




Generator Carbureter Superheater Scrubber Condenser 

Fig. 101. — ^Lowe Water-gas Plant. 

is known as the Lowe type of apparatus. Either anthracite coal or coke 
may be used as fuel. The former should preferably show less than 7 per 
cent volatile on ignition, not more than 12 per cent ash having a high fusing 
point to avoid '^ clinkering," also small percentages of moisture and sulphur. 

256 



WATER-GAS AND OII^GAS TARS AND PITCHES 257 

The fuel is charged into the generator and allowed to undergo partial 
combustion by admitting a limited amount of primary air through the 
pipe A below the bed of fuel. The gases then pass downward through the 
carbureter and the combustion almost completed by means of a care- 
fully regulated supply of secondary air introduced through the valve B. 
From the carbureter the products pass upward through the superheater, 
where the temperature may be controlled by admitting a tertiary supply 
of air through the valve C, and the products of combustion finally passed 
into the atmosphere through the stack D. 

When the fuel in the gas-generator has been properly ignited, and 
the carbureter and superheater brought to the required temperatures, the 
air blasts are cut off in the sequence: C, B, and A, and the stack valve D 
closed. Steam is introduced into the generator through the valve E below 
the bed of incandescent fuel and results in the production of " blue-gas," 
according to the following reaction: C + H20 = CO+H2. This is passed 
into the carbureter where it mingles with a spray of carbureting oil kown 
as " gas oil " introduced through F. The mixture is passed downward 
through the carbureter whereby the oil becomes vaporized. From the 
carbureter, the gases are passed up through the superheater, the tempera- 
ture of which is very carefully regulated at 1200-1300° F. to crack the 
oil vapors into permanent gases, and this incidentally results in the for- 
mation of tarry matters. 

The formation of carbon monoxide and hydrogen by the action of 
steam on incandescent fuel results in a lowering of the temperature on 
account of the absorption or storing up of thermal energy, so that it 
becomes necessary to turn off the steam and reintroduce the air. The 
'' blowing up " process is thus repeated. At the same time the oil spray 
is turned off the carbureter, as its temperature has fallen to a point below 
which the oil would not be supeiheated sufficiently to convert it into a 
permanent gas. 

The supplies of air, steam and oil are carefully metered and the tem- 
peratures controlled by electric pyrometers within 20 to 40° C. The 
'' blowing " or '^ up run " lasts three to five minutes, and the ''gas making^' 
or '' down run " lasts tw^o to four minutes. 

The water-gas and accompanying tarry vapors derived from the gas 
oil are passed from the superheater through the pipe G into a wash-box 
which corresponds to the hydraulic main in a coal-gas plant. The vapori- 
zation of water in the wash-box reduces the temperature of the gases from 
1200 to 190° F. The gases next pass upward through a scrubber filled 
with shelves carrying a checker-work of wooden slats (Fig. 63) over which 
water is allowed to trickle. From the scrubber the vapors are passed 



258 



ASPHALTS AND ALLIED SUBSTANCES 



downward through a water-cooled condenser (Fig. 60) which reduces 
their temperature to 140-150'' F., and thence into a rehef gas-holder. 
Most of the tar is condensed in the wash-box and smaller quantities in 
the scrubber and condenser. An exhauster draws the gases through the 
foregoing train of aparatus and then forces them through a tar extractor, 
usually of the P. & A. type (Fig. 69), to remove the last traces of tar. 
The temperature of the gases as they pass through the tar extractor is 
in the neighborhood of 110 to 115° F. They are finally passed through 
the purifier filled with trays of ferric oxide to remove the sulphur com- 
pounds, and thence into the main gas holder. 

The carbureting oil, known also as '^ gas oil " or " enriching oil " 
varies in composition depending upon the character of the petroleum 
from which it is derived. Experience demonstrates that oils obtained from 
a paraffine base petroleum generate the greatest proportion of gas and the 
smallest quantity of tar. Oils containing unsaturated straight-chain 
hydrocarbons are less efficient, and those containing unsaturated ring 
hydrocarbons are almost valueless. The yield of tar expressed in per- 
centage by volume, based on the various types of petroleum used, is as 
follows : 

ParafBne base naphtha 2-4% 

Paraffine base gas oil 6-10% 

Paraffine base crude oil 8-12% 

Asphaltic base gas oil 10-15% 

Asphaltic base crude oil 12-18% 

The effect of the temperature on the decomposition of an asphaltic 
petroleum is shown in the following table: 



Temperature, 


Cu. Ft. Gas 


Tar, 


Coke, 


Deg. C. 


per Gal. Oil. 


Per Cent. 


Per Cent. 


711 


56.4 


28.0 


1.83 


741 


61.5 


29.4 


2.43 


751 


63.7 


26.2 


3.63 


789 


68.0 


24.2 


3.45 


832 


80.3 


11.9 


12.43 



The quantity of carbureting oil ordinarily used varies from 3.5 to 4.5 
gal. per ton of anthracite coal. 

Water-gas tar on account of its low specific gravity forms an emulsion 
with the associated water and separates with great difficulty. The water 
is practically free from ammonia compounds, thus differing from coal tar, 
and the tar is very much thinner in consistency, containing but a small 
amount of free carbon. The methods for dehydrating crude water-gas 



WATER-GAS AND OIL-GAS TARS AND PITCHES 259 

tar have been described (pp. 180-lcS3), and the dehydrated water-gas 
tar compKes with the following tests: 

(Test 1 ) Color in mass Black 

(Test 2a) Homogeneity to the eye Uniform 

(Test 26) Homogeneity under microscope Absence of carbonaceous 

matter 

(Test 7) Specific gravity at 77° F 1 . 05-1 . 15 

(Test 8) Viscosity Very liquid 

(Test 13) Odor on heating Characteristic "gas-like" 

(Test 15a) Fusing-point (K. and S. method) Less than 0° to 10° F. 

(Test 16) Volatile matter at 500° F., 4 hrs 60-85% 

(Test 17o) Flash-point Low 

(Test 19) Fixed carbon 10-20% 

(Test 20) Distillation: 

Up to 110° C. (Naphtha) - 5%, by weight (Sp.gr. 0.85-0.90) 

110-170° C. (Light oils) 0.5-5.0% (Sp.gr. 0.88-0.90) 

170-235° C. (Middle oils) 5 -35% (Sp.gr. 0.98-1 .00) 

235-270° C. (Heavy oils) 7 -30% (Sp.gr. 1 .00-1 .07) 

270-350° C. (Anthracene oil) 10 -25% (Sp.gr. 1 .07-1 . 10) 

Residue (Watei-gas-tar pitch) 20 -60% 

(Test 21a) Solubility in carbon disulphide 98 -100% 

(Test 216) Non-mineral matter insoluble - 2% 

(Test 21c) Mineral matter - 1% 

(Test 22) Carbenes - 2%o 

(Test 23) Solubility in 88° naphtha 20 - 75% 

(Test 26) Carbon 90 - 95% 

(Test 27) Hydrogen 3 - 6% 

(Test 28) Sulphur 0.5- 2.0% 

(Test 29) Nitrogen 0.5- 1.0%, 

(Test 30) Oxygen 1 -2% 

(Test 32) Naphthalene Less than 10% 

■(Test 33) Paraffine -5% 

(Test 35) Sulphonation residue -15% 

(Test 37) Saponifiable constituents 1 Tr. -2% 

(Test 41) Diazo reaction Yes 

(Test 42) Anthraquinone reaction Yes (Less than 5%) 

Weiss reports ^ that water-gas tar has a coefficient of expansion for 1° F. (length 
= 1) of 0.00035-0.00038. According to Downs and Dean,^ water-gas tar contains 
substantial amounts of benzene, toluene, xylenes, naphthalene and anthracene. The 
nitrogenous bases and phenols are absent or nearly so. Weiss reports further that 
the percentage of free carbon varies from 1.04 to 1.087 per cent, with water-gas 
tars ranging in specific gravity from 1.078-1.090.^ 

Oil-gas Tars. These are manufactured from petroleum alone without 
the use of coal or coke. Several methods have been used, all embodying 
the same principle but differing in detail, the most important of which 
are as follows: 

Pintsch Gas. This is manufactured by spraying petroleum in a closed 
retort constructed of iron or fire clay and heated to a temperature of 900 
to 1000° C. by combustion of oil, gas or tar underneath. The shape of 

yj. Franklin Inst. 172. 277, 1911. 

2 J. Ind. Eng. Chem., 3, 108, 1911; also 6, 366, 1914. 

3 7. Franklin Inst., 172, 277, 1911. 



260 



ASPHALTS AND ALLIED SUBSTANCES 



the retort is shown in Fig. 102. The vapors pass to the rear and thence 
downward and through a lower chamber into the hydrauhc main in front. 
The gases are passed successively through a scrubber, condenser and 
purifier. 

Recently a modified form of apparatus has been used for manufactur- 
ing Pintsch gas under a high pressure, consisting of a heavy steel con- 
tainer filled with a checker-work of brick. The checker- work is first 
heated to a high temperature by introducing steam and air. Sometimes 
the resulting tar is used instead of the oil during the heating-run. When 
the proper degree of heat is obtained the air is shut off and oil with a small 
amount of steam is sprayed in under pressure. The main advantage 
resulting from the use of pressure is the greater yield of gas. 




Oil and I 
Steam c 




Fig. 102.— Pintsch Gas Retort. 



TWrnmenerator 

Fig 



Wash Box 



103. — Oil-water Gas Plant. 



Pintsch gas is used extensively for railroad and buoy lighting. It 
may be stored in holders under a pressure of 5 to 25 atmospheres, without 
suffering in illuminating power as would prove to be the case with most 
other gases adapted for lighting purposes. 

About 10 per cent tar is recovered in the Pintsch process, the charac- 
teristics of which will be described under the heading " oil-gas tar " below. 

Oil-water Gas. This process is used almost exclusively on the Pacific 
coast for manufacturing illuminating gas, owing to the absence of coal 
deposits.^ 

The installation is shown diagrammatically in Fig. 103. The generator 
and superheater are filled with checker-works of brick. Assuming that 



i"The Development of Oil-gas in California," Proc. Am. Gas Inst., 4, 413, 1909. 



WATER-GAS AND OIL-GAS TARS AND PITCHES 261 

the temperature of the brick work has been previously brought to the proper 
temperature for igniting petroleum vapors, the stack valve A is opened 
and valve B closed. For the first three minutes air (at a pressure of 7 
to 9 in.) and steam (at a pressure of 35 lb.) are admitted through the 
valves C and D respectively at the top of the generator to start the run. 
At the 'end of the three minutes, petroleum heated to 150° F. is introduced 
through D (at a pressure of 8 lb.), and the heating continued for nine 
minutes. Then air is turned off at C, valve B opened, and valve A closed 
in the sequence named. Oil and steam are then introduced through the 
valves D and E, and allowed to continue eight minutes, whereupon the 
oil is shut off, and steam alone blown through the generator and super- 
heater for two minutes to purge the apparatus of oil vapors. From the 
wash-box, the vapors are passed through scrubbers filled with a checker- 
work of wooden slats as shown in Fig. 63. 

The top of the superheater acts as a reservoir to store heat. The take- 
off valve B is at the centre, because experience has shown that if the oil 
vapors were allowed to traverse the entire superheater during the gas- 
making period, the illuminants would be decomposed into methane, 
hydrogen and lampblack. The heat is controlled by the two sets of burn- 
ers D and E. If the checker-w^ork becomes overheated, more oil is intro- 
duced, and conversely if the temperature falls too low, less oil is used. 
If the temperature of the apparatus is too high, lampblack will separate 
out in the wash-box, while if it is too low an excessive quantity of tar 
will be produced. The tar is very similar to Pintsch-gas tar in its physical 
and chemical properties. During the gas-making period, the oil is kept 
at a pressure of 20 lb. in the generator and 25 lb. in the superheater. 

It requires about 8 to 8J gal. of crude oil per 1000 sq.ft. of gas, of which 
about one-fifth is required for heating and four-fifths for gas-making. 

Blau Gas. This is a further development of Pintsch gas, and is 
made by cracking oil vapors at a temperature lower than in the Pintsch 
process (i.e. 550 to 600° C), but in a similar form of retort. The resulting 
gases are first purified by passing in the usual manner through hydraulic 
mains, coolers, cleaners and scrubbers to remove the tar, which amounts 
to 4-6 per cent of the oil used, and then compressed in a three- or four- 
stage compressor to 100 atmospheres, which causes the high boiling-point 
constituents to liquefy and absorb a large proportion of the non-lique- 
fiable gases. The excess of the latter is used for running the compressor 
and heating the retorts. 

The compressed Blau gas is so constituted that upon releasing the 
pressure, the dissolved and Hquefied constituents are evolved in such pro- 
portions that the composition of the gaseous mixture remains constant. 



262 ASPHALTS AND ALLIED SUBSTANCES 

Blau gas is used principally for marine lighting purposes and transported 
in cylinders of about 1 cu.ft. capacity, carrying 20 lb. of the compressed 
gas, which will expand to about 250 cu.ft. at atmospheric pressure. Its 
illuminating value is greater than that of Pintsch gas. 

The tar recovered from the Blau gas process is similar in its physical 
and chemical properties to the oil-gas tars described previously.^ 

Properties of Oil-gas Tars. Dehydrated oil-gas tars produced by the 
Pintsch process, the oil-water gas process and the Blau gas process comply 
with the following characteristics: 

(Test 1) Color in mass Black 

(Teat 2a) Homogeneity to the eye Uniform 

(Test 26) Homogeneity under the microscope Comparatively free 

from carbonaceous 
matter. 

(Test 7) Specific gravity at 77° F . 95-1 . 10 

(Test 8) Viscosity Moderate 

(Test 9c) Consistency at 77° F 

(Test 13) Odor on heating Like water-gas tar 

(Test 15a) Fusing-point (K. and S. method) <0°-20° F. 

(Test 16) Volatile matter at 500° F., in 4 hrs 35-70% 

(Test 17a) Flash-point Low 

(Test 19) Fixed carbon 10- 25% 

(Test 21a) Soluble in carbon disulphide 98- 100% 

(Test 216) Non-mineral matter insoluble 0- 2% 

(Test 21c) Mineral matter 0- 1% 

(Test 22) Carbenes 0- 2% 

(Test 23) Solubility in 88° naphtha 50- 85% 

(Test 28) Sulphur <1% 

(Test 30) Oxygen 1- 2% 

(Test 32) Naphthalene Trace 

(Test 33) ParafEne 0- 5% 

(Test 35) Sulphonation residue 20- 40% 

(Test 37) Saponifiable constituents Trace 

(Test 41) Diazo reaction Yes 

(Test 42) Anthraquinone reaction Yes 

When asphaltic petroleums are used to produce oil-gas tar, paraffine 
will be absent, but when non-asphaltic or mixed-base petroleums are used, 
it will be present in quantities not exceeding 5 per cent. 

Water-gas and oil-gas tars are distinguished from coal-tars by the following. 

(1) Absence of associated ammonium compounds in the aqueous liquor. 

(2) Lower specific gravity. 

(3) Smaller percentage of "free carbon" (non-mineral matter insoluble in car- 
bon disulphide). 

(4) Larger proportion soluble in carbon disulphide. 

(5) Presence of paraffine wax -when mixed-base or non-asphaltic petroleums have 
been used. 

> "Blau Gas: A New Gcs for Illuminating, Heating, and Power Purposes," by William Hallock, 
/. Soc. Chem. Ind , 27, 550, 1908; "The Manufacture and Use of Blau Gas," by Hugo Lieber, 
Met. Chem., Eng. 12, 153, 1914. 



WATER-GAS AND OIL-GAS TARS AND PITCHES 



263 



(6) A substantial proportion of sulphonation residue, which considered in con- 
nection with the small percentage of mineral matter distinguishes them from blast- 
furnace tars. 

Oil-gas tar may be distinguished from water-gas tar by the following: 

(1) Oil-gas tar as a rule has a lower specific gravity. 

(2) Water-gas tar yields a smaller percentage of sulphonation residue. 

Refining of Water-gas and Oil-gas Tars. Oil-gas and water- 
gas tars when suitably dehydrated may be distilled in accordance with 
the methods used for '^ coal tar " (p. 246). Sometimes the water-gas-tar 
pitch or oil-gas-tar pitch is mixed with coal-tar pitch in suitable propor- 
tions. 

Properties of Water-gas-tar Pitch and Oil-gas-tar Pitch. Water-gas- 
tar-pitch and oil-gas-tar pitch comply with the following tests: 



(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 
(Test 10) 
(Test 11) 
(Test 13) 
(Test 14a) 
(Test 15a) 
(Test 156) 
(Test 15c) 
(Test 16) 
(Test 17a^ 
(Test 19) 
(Test 21a) 
(Test 216) 
(Test 21c) 
(Test 22) 
(Test 23) 
(Test 28) 
(Test 30) 
(Test 33) 
(Test 35) 
(Test 37) 
(Test 41) 
(Test 42) 



Color in mass 

Homogeneity to the eye 

Homogeneity under the microscope 

Aged surface 

Fracture 

■Lustre 

Streak 

Specific gravity at 77° F 

Consistency at 77° F 

Susceptibility factor 

Ductility 

Tensile strength at 77° F 

Odor on heating 

Behavior on melting 

Fusing-point (K. and S. method) . . 
Fusing-point (B. and E, method) . . 

Fusing-point (cube method) 

Volatile matter 500° F., 4 hrs 

Flash-point 

Fixed carbon 

Solubility in carbon disulphide 

Non-mineral matter insoluble 

Mineral matter 

Carbenes 

Solubility in 88° naphtha 

Sulphur 

Oxygen 

Paraffine 

Sulphonation residue 

Saponifiable matter 

Diazo reaction 

Anthraquinone reaction 



Water-gas-tar 
Pitch. 



Black Black 

Uniform Uniform 

Small amount of carbon visible 



Oil-gas-tar 
Pitch. 



Variable 


Variable 


Conchoidal 


Conchoidal 


Bright 


Bright 


Black 


Black 


1.10-1.20 


1.15-1.30 


10-100 


10-100 


>100 


>100 


Variable 


Variable 


Variable 


Variable 


Characteristic 


Characteristic 


ass rapidly from 


solid to liquid Bta< 


80-275° F. 


80-275° F. 


100-300° F. 


100-300° F. 


110-320° F. 


110-320° F. 


5-15% 


5-15% 


300-400° F. 


300-400° F. 


25-40% 


20-30% 


85-98% 


85-98% 


2-15% 


2-15% 


0- 1% 


0- 1% 


2-15% 


2-20% 


50-80% 


65-85% 


<4% 


<4% 


0- 2% 


0- 2% 


0- 5% 


0- 5% 


0-15% 


20-40% 


0- 1% 


0- 1% 


Yes 


Yes 


Yes 


Yea 



264 



ASPHALTS AND ALLIED SUBSTANCES 



Representative samples of water-gas-tar pitch and oil-gas-tar pitch tested by 
the author gave the following results: 





Water-gas-tar 
Pitch. 


Oil-gas-tar 
Pitch. 


(Test 3) Appearance surface aged 1 week 

(Test 7) Specific gravity at 77° F 

(Test 96) Penetration at 115° F. (50 g., 5 sec.) 

Penetration at 77° F. (100 g., 5 sec.) 

Penetration at 32° F. (200 g., 60 sec.) 

(Test 9c) Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

(Test 9d) Susceptibility factor 

(Test 106) Ductility at 115° F 

Ductility at 77° F 

Ductility at 32° F 

(Test 11) Tensile strength at 115° F 

Tensile strength at 77° F 

Tensile strength at 32° F 

(Test 15c:) Fusing-point (K. and S. method) 

(Test 156) Fusing-point (B and R. method) 

(Test 15c) Fusing-point (cube method) 


Bright 
1.18 
235 
20 
2 

1.0 
20.2 
>100 
>100 
50 
85 


0.2 
4.0 
7.2 
102° F. 
120° F. 
134° F. 
10.2% 
328° F. 
27.7% 
97.3% 
2.5% 
0.2% 
9.2% 
8.2% 
0.2% 


Bright 

1.20 
166 

6 

1 

2.7 
28.0 
>100 
>100 
65 
44 



0.4 

7.5 

6.0 
128i° F. 
149^^ F. 
159^° F. 


(Test 16) Volatile matter 500° F., 4 hrs 


7.8% 


(Test 17a) Flash-point 


365° F. 


(Test 19) Fixed carbon 


25.1% 


(Test 21a) Soluble in carbon disulphide 


87.8% 


(Test 216) Non-mineral matter insoluble 

(Test 21c) Mineral matter 

(Test 22) Carbenes 

(Test 35) Salphonation residue 


11.8% 
0.4% 
4.7% 

30.7% 


(Test 37) Saponifiable matter 


0.7% 



Water-gas-tar and oil-gas-tar pitches may be distinguished from coal-tar pitches by: 

(?) The small percentage of "free carbon" (non-mineral matter insoluble in 
carbon disulphide). 

(2) The possible presence of parafiine wax (when non-asphaltic or mixed-base 
petroleums are used). 

On the other hand, water-gas-tar pitch may be distinguished from oil-gas-tar 
pitch by the following: 

(1) Lower specific gravity of water-gas-tar pitch. 

(2) Larger percentage of sulphonation residue from oil-gas-tar pitch. 

Both of these pitches are largely susceptible to changes in temperature, they 
are highly resistant to the prolonged action of moisture, and are adapted for man- 
ufacturing low-priced solvent paints because of their ready solubility in "coal-tar 
naphtha." 



CHAPTER XIX 



PETROLEUM ASPHALTS 
VARIETIES OF PETROLEUM 

" Petroleum asphalts '' are obtained from petroleums by distillation, 
blowing with air at elevated temperatures, and refining with sulphuric 
acid. These methods will be described in greater detail later. 

Petroleum as it occurs m different parts of the world, varies widely 
in composition. Certain varieties are composed entirely of open chain 
hydrocarbons (p. 30), others are made up exclusively of cyclic hydro- 
carbons (p. 34), and still others occur showing every possible gradation 
between these two extremes. Numerous classifications have been pro- 
posed, based on its chemical composition in general, or the presence of a 
substantial proportion of characteristic bodies, such as the paraffine series 
of hj^drocarbons, the naphthene series, sulphur derivatives, nitrogenous 
bodies, benzols, terpenes, etc.^ 

From the standpoint of the solid hydrocarbons present, petroleums 
may be divided into three groups, viz.: 

(1) Bearing a substantial quantit}^ of solid paraffines. 

(2) Bearing a substantial proportion of asphaltic bodies. 

(3) Of mixed composition, bearing both solid paraffines and asphaltic 
bodies. 

The solid paraffines are usually associated with open chain hydro- 
carbons, and the asphaltic bodies with the cyclic hydrocarbons. The 
two extreme types of petroleum, and the innumerable intermediate groups 
are represented empirically as follows: 

Intermediate 
Types 



Extreme Types 



Extreme Types 



Composed of open-chain hydro- 
carbons. 

Presence of solid paraffines. 

Absence of asphalt (i.e., "non- 
asphaltic") 

Sulphur and nitrogenous bodies 
may or may not be present. 



Mixed Base 
Petroleums ' 



Composed of cyclic (aromatic) 
hydrocarbons. 

Absence of solid paraffines. 

Presence of asphalt (i.e., "as- 
phaltic") 

Sulphur and nitrogenous bodies 
generally present. 



1 For a detailed consideration of this complex subject, the reader is referred to the excellent 
works of C. Engler and H. v. Hofer, C. F. Mabery, K. W. Charitschkoff, N. A. Kwjatkowsky, 
M. A. Rakusin, etc. 

265 



266 ASPHALTS AND ALLIED SUBSTANCES 

Open chain hydrocarbons predominate in the petroleums produced in 
the Appalachian field (Pennsylvania, New York, southeastern Ohio, 
West Virginia, Kentucky and Tennessee), the Lima-Indiana field (em- 
bracing western Ohio and Indiana), the Canadian and the Alaskan oil 
fields. These are non-asphaltic, and generally carry solid paraffines. 

Both open-chain and cyclic hydrocarbons are present in the petroleums 
produced in the Illinois, the Mid-continental (extending over Kansas, 
Oklahoma, northern Texas and northern Louisiana in the neighborhood 
of Caddo and De Soto) and in the Mexican oil fields. These are representa- 
tive of the mixed-base petroleums, and carry both asphalt and the solid 
paraffines. 

Cyclic hydrocarbons predominate in petroleums produced in the Gulf 
field (including southern Texas and southern Louisiana), the California 
field and the Trinidad field. These are representative of the asphaltic 
petroleums, and are usually free from solid paraffines. 

The following refineries producing petroleum asphalts were reported 
operative in the United States during 1916: 

California: 16 refineries utilizing California crude oil 

Illinois: 3 refineries utilizing Illinois oil 

1 refinery utilizing Kansas and Oklahoma oils 
Indiana: 1 refinery utilizing Oklahoma and Kansas crudes 
Louisiana: 1 refinery utilizing Texas crude 

2 refineries utilizing Mexican crude 
Maryland: 3 refineries utilizing Mexican crude 

Missouri: 1 refinery utilizing Oklahoma and Kansas crudes 

New Jersey: 2 refineries utilizing Mexican crude 

New York: 1 refinery utilizing Mexican crude 

Ohio: 1 refinery utilizing Mexican and Illinois crudes 

Pennsylvania: 1 refinery utilizing IMexican crude 

Texas: 3 refineries utilizing Texas crude 

2 refineries utilizing Texas and Mexican crudes 
1 refinery utilizing Mexican crude exclusively. 

PRODUCTS OBTAINED FROM PETROLEUM 

There is great confusion in the nomenclature of the products derived 
from the distillation and refining of petroleum. Many terms have been 
suggested, both scientific and proprietary, but no standard system of 
terminology has been adopted for the purpose, much as it would be 
welcomed by the industry. 

In general, petroleum distillates are classified into seven groups, and 
the residual products into six. Each group is designated by various names, 
in some cases depending upon the use to which the material is to be put, 
in others, upon its physical characteristics, and in still others by fanciful 
terms having no special significance. These will be considered in greater 
detail. 



PETROLEUM ASPHALTS 267 



Distillates 



(1) Gasoline. The best practice restricts the use of the word "gasoline" to 
light petroleum distillates suitable for gasification in a vaporizer, as for example, 
in a gas machine, gasoline torch, gasoline stove, automobile carburetor, etc. The 
term gasoline has been variously referred to by the following expressions: 

Petroleum Ether. This is sometimes applied to products ranging in specific 
gravity from 0.590-0.700 (108-70° Baumc), occasionally termed cymogene (108-90° 
Baume, equivalent to 0.590-0.636), canadol (85-70° Baume, equivalent to 0.650-0.700), 
rhigolene (103° Baume, equivalent to 0.600) or Sherwood oil (boiling between 40 
and 70° C). These expressions are rarely used. 

Petroleum Spirits. A term rarely applied to products ranging in specific gravity 
from 0.679-0.745 (76-58° Baume). 

Light Petroleum. A term infrequently applied to distillates varying in specific 
gravity from 0.642-0.729 (88-62° Baume). 

Ligroin. A name indiscriminately applied abroad to the lower boiling-point 
fractions; S3Tionymous with "petrol" or "light petroleum"; used to designate 
gasoline for operating automobile motors. 

(2) Naphtha. The terms "gasoline" and "naphtha" are generally used syn- 
onymously, but the best practice restricts the word "naphtha" to light petroleum 
products used as solvents, as for example by varnish and paint makers, soap makers, 
cleaners, etc., fractioned after the gasoKne and before the kerosene. The following 
terms have also been employed to designate this product: 

Benzine or Benzoline. These are used to a limited extent synonymously for 
naphtha. . 

"F. M. & P. Naphtha." This is an abbreviation for "varnish makers and 
paint naphtha," and is used to designate a solvent suitable for manufacturing 
varnishes and paints. 

Turpentine Substitute. A closely fractioned distillate between naphtha and kero- 
sene, having a fairly high flash-point (between 80 and 105° F., open cup test). 

Cleaning Oil. A low boiling-point naphtha used for "dry cleaning" purposes. 

Note. Naphthas are distinguished by their specific gravity, expressed in degrees 
Baume; thus 62° naphtha refers to a product having a gravity of 62° Baum6 
(sp. gr. 0.729), etc. 

(3) Kerosene. This term is applied to the distillate fractioned after the "naphtha" 
and before the "gas or fuel oil," suitable for burning in lamps or stoves by means 
of a wick, either for illuminating or heating purposes. Kerosenes are distinguished 
by their gravity expressed in degrees Baume, by their fire test (temperature at 
which the vapors ignite), or by their color (thus, "W. W." or "water-white" 
kerosene is colorless, "prime-white" has a straw color, "standard-white" a pale 
yellow color, etc.). The following terms have been used synonymously for kerosene, 
viz.: illuminating oU, lamp oil, burning oil, stove oil, coal oil, carbon oil, white 
on, head-light oil, signal oil, engine distillate, etc. 

(4) Gas or Fuel Oil. These expressions, also sometunes designated "intermediate 
oils," or "middlings," are applied to the distillate obtained between "kerosene" 
and "lubricating oil." They usually have a high boiling-point (600-650° F.) and 
a low gravity (30-42° Baume). This distillate is termed "gas oil" when it is 
used for enriching illuminating gas (p. 231) or for manufacturing carbureted 
water gas (p. 256), and it is called "fuel oil" when used for power or heating 



268 ASPHALTS AND ALLIED SUBSTANCES 

purposes (viz., for firing steam boilers, locomotives, heating retorts, smelting, etc.). 
''Fuel oil" is sometimes referred to under the names "power distillate," ''orchard 
oil," or "smudge oil" (i.e., when burnt in orchards to keep away frost). 

(5) Lubricating Oil. This distils over after the "gas or fuel oil," In the 
case of parafiine-bearing petroleums, paraffine wax is separated from the lubricating 
oil by cooling and filtering. Lubricating oil has been exploited under various 
fanciful names, likewise appellations indicative of the use for which it is intended, 
including the following: neutral oil, spindle oil, cylinder oil, mineral sperm oil, 
mineral seal oil, mineral colza oil, paraffine oil, straw oil, machine oil, engine oil, 
gas-engine oil, automobile oil, compressor oil, ice-machine oil, dynamo oil, harvester 
oil, cream-separator oil, transformer oil, floor oil, etc. 

' Lubricating oils are designated by their viscositj^ (in terms of the Saybolt A 
viscosimeter), their specific gravity (degrees Baume), and flash-point. For certain 
purposes they must withstand low temperatures without solidification, and for 
others, high temperatures without carbonization or appreciable loss of volatile con- 
stituents. 

(6) Paraffine Wax. This is derived from paraffine-bearing petroleums, being 
separated from the lubricating oil and paraffine distillates by crystalhzation at low 
temperatures and filter-pressing. It is distinguished by its color and melting-point. 
The terms "paraffine scale" and "scale wax" are generally applied to the low 
melting-point variety, and "refined paraffine wax" to the harder variety. Its 
melting-point varies from 100-135° F. (see p. 307). 

(7) Wax Tailings. This represents the fraction obtained in the dry distillation 
of petroleums, and recovered immediately prior to coking. It is peculiar in its 
properties and generally free from parafine wax (see p. 310). 



Residues 

The following represent the various classes of residual products obtained in dis- 
tilling petroleums: 

(1) Residual Oil. This term is applied to the residue obtained from the 
dry distillation of paraffine-bearing petroleum, the steam or the dry distillation of 
mixed-base petroleums, and the steam distillation asphalt-bearing petroleum. It 
is characterized by being liquid or semi-liquid at room temperatures. The following 
terms are used synonymously with residual oil, viz.: asphaltum oil, liquid asphalt, 
black oil, flux oil, petroleum tailings and sometimes also fuel oil. When it is derived 
from paraffinaceous petroleum it is sometimes called "paraffine flux." 

Note. Road Oil and Dust-laying Oil, are terms applied to the residual asphalts of 
liquid to semi-liquid consistency used for laying particles of dust on roads, includ- 
ing also the harder residual asphalts rendered liquid by dissolving in "gas or 
fuel oil," the solvent being supposed to evaporate slowly in time, leaving the 
dust particles covered with an adherent film. 

(2) Residual Asphalt. This is applied to the residues obtained from the steam 
or dry distillation of mixed petroleums and the steam distillation of asphalt-bearing 
petroleum. It is characterized by being semi-solid to solid at room temperature. 

Note. Road-binder. This term is applied to residual asphalt distilled to the 
proper consistency, or mixtures of residual asphalt with blown asphalt. These 
are not supposed to evaporate and are used for binding road-making materials 



PETROLEUM ASPHALTS 269 

together. The term is used synonymously with "carpeting medium" and "seal- 
coating material." 

(3) Blown Asphalt. A term used to designate the products obtained by blow- 
ing air through residual oils at elevated temperatures (see p. 287). This term 
is used synonymously with "oxidized asphalt," "oxygenized asphalt," and "con- 
densed asphalt." 

(4) Sulphurized Asphalt. This term is applied to the product obtained by 
heating residual oil or residual asphalt with sulphur at a high temperature. 
This name is also used synonymously with "Dubbs asphalt," "Pittsburgh flux," 
or "Ventura flux." 

(5) Sludge Asphalt. This term is applied to the asphalt-like product separated 
from the acid sludge produced in the refining of petroleum distillates with sul- 
phuric acid. (See p. 303.) It is also known under the names "acid asphalt" 
and "acid-sludge asphalt." 

(6) Coke. This is the residue produced in the dry distillation of non-asphaltic 
or mixed-base petroleums (see p. 282). 

In addition to the foregoing, the following product is obtained by treating petro- 
leum in a special way: 

Petrolatum. This name is applied to a product obtained by diluting crude 
paraffinaceous petroleum with naphtha and then subjecting the mixture to a low 
temperature, when a residue settles out, which is drawn off and distilled until the 
naphtha is removed, whereupon it is decolorized by filtering through fuller's earth. 
It is likewise known under the names vaseline, petroleum jelly, liquid paraffine, etc. 



DEHYDRATION OF PETROLEUM 

Nearly all crude petroleums carry more or less water, some being 
entrained mecbxanically, and in other cases held in a state of emulsion. 
Before the petroleum can be distilled, the water must be separated. 
The following methods are used for the purpose: 

(1) Settling. This method is similar to that described under tars on p. 181, 
and is onl}^ of value when the water is not emulsified with the oil. The oil is 
maintained at 100-150° F., with steam coils at the bottom of the tank to increase 
its fluidity and promote the water settling. 

(2) Heating under Pressure. This method has given good results with certain 
viscous California petroleums (especially those obtained from the Coalinga district), 
in which the water is partly entrained mechanically, and partly carried in a state 
of emulsion. The method consists in passing the oil through coils of pipe heated 
in a furnace to 250-300° F. under pressure.^ Upon releasing the oil at atmospheric 
pressure in an air-cooled tower 18 ft. high and about 16 in. in diameter, the 
globules of water are converted into steam and this with the light oils, are led 
from the top into a water-cooled condenser, where the oils are recovered. The 
residual oil is drawn off at the bottom. The plant is illustrated in Fig. 104. 
Another alternative consists in heating the petroleum under pressure in a closed 

1 Hardison, Trans. Am. Inst. Mining Eng., 99, 637, 1915. 



270 



ASPHALTS AND ALLIED SUBSTANCES 



receptacle to allow the water and impurities to settle out, and then pernaitting 
it to cool quietly. 1 

(3) Milliff Hot-air System. Air heated to 1000° F. is blown through a per- 
forated pipe into a tank carrying the cold oil. This converts the water into steam 
and vaporizes a small quantity of light oils which are recovered by passing the 
vapors through a condenser. 



^—-Vapor to 
Coudeusing 
Coils 




ium///m///////////m 



From Eeceiving Tanks^ Separatoj 

From "The American Petroleum Industry," by Bacon and Hamor. 

Fig. 104. — Plant for Dehydrating Petroleum. 



(4) Electrical Method. This has been perfected by Cottrell, and is similar to 
Method 7 described under " Tar" on p. 180, consisting in subjecting the crude petro- 
eum to a current of 10,000 to 15,000 volts. 



METHODS OF REFINING PETROLEUM 



The dehydrated petroleum is separated into various commercial 
products by fractional distillation ^ (see p. 266). The process may be 
intermittent or continuous. Both systems are in vogue, and each will 
be considered separately. 

Intermittent Distillation Processes. Petroleum may be distilled inter- 
mittently in either horizontal or vertical stills. Horizontal stills are set 
in brick walls which may be carried up on all four sides so that the still 
is completely enclosed, or else the ends may be allowed to project free. 
In the usual form, cast-iron lugs are riveted to the sides and allowed to rest 
on the brick work. In another form, metal loops are riveted to the top of 
the still, to engage hooks supported by " I *' beams resting directly on the 

1 U. S. Pat. 890,762 of Jun. 16, 1908 to J. A. Dubbs. 

2 "American Petroleum Industry," by Bacon and Hamor; "The Manufacture of Petroleum 
Products," by F. G. Robinson, Met. Chem. Eng., H, 389, 1913; "Das Erdol," by Engler-Hofer, 
loc. cit. 



PETROLEUM ASPHALTS 



271 



brick walls or on metal columns outside of the setting. The walls are 
usually carried up half-way, the ends and upper portion of the still being 
covered with some non-conductive material to prevent radiation and 
loss of heat. 

Heating is effected by means of gas, oil or coal, depending upon which 
may be procured cheapest locally. Gas or oil is introduced through 
specially constructed burners, and coal is burnt on a simple form of grate. 
The stills may be fired either at the ends or the sides, the latter giving a 
more uniform distribution of heat. Modern stills are made large enough 
to carry 1000 to 1500 barrels (of 42 gal. each). The diameter varies 




Fig. 105. — Horizontal Petroleum Stills. 



from 10 to 15 ft., and the length from 40 to 50 ft. Two forms of an 
800- to 900-barrel still are shown in Figs. 105A and 1055, the former being 
equipped with a dome and the latter without. 

A vertical still of greater diameter than height with a dome-shaped 
top and a concave bottom was formerly used extensively in this country. 
It is popular abroad, and is occasionally encountered in the United States, 
but is rapidly going out of use (some are used in the Kansas and Pennsyl- 
vania oil fields, 16 ft. in diameter and 10 ft. high, mounted over a series 
of arches). 

The vapors from the still (A) are led to the condenser, consisting of 
coils of pipe (M) surrounded with water in the tank (L). The con- 
densate is conveyed through " running lines " (0) to the " tail house " (N) 
where the lines are provided with " look-boxes " (P) so the operator may 



272 



ASPHALTS AND ALLIED SUBSTANCES 



ascertain the gravity and observe the appearance of the distillate. From 
the look-boxes the lines connect with a manifold (Q) to deflect the 
" stream " into any desired receiving tank. The installation is illustrated 
diagrammatically in Fig. 106. The fuel is burnt on the grate (E), the 
hot gases passing over the fire-arch (C) into the flue (D). The ash-box 
is represented by (B), the pipe for introducing steam by (G), and the 
pipe for drawing off the residual by (H). 

The intermittent distillation may be carried on either with or without 
the use of steam. When steam is employed, the process is known as 
'' steam distillation," otherwise it is termed " dry distillation." 

(1) Dry Distillation. This is sometimes termed the " straight " or 
" destructive " or '^ cracking " process, by means of which a certain 




Fig. 106. — Plant for Refining Petroleum. 



proportion of the higher boiling-point constituents decompose or break 
down, forming correspondingly larger yields of the low boiling-point 
constituents. The dry distillation process is accordingly used when 
the distiller wishes to produce the maximum amount of gasoline and illu- 
minating oil, or in cases where the crude is unfit for manufacturing lubri- 
cating oil. Non-asphaltic petroleums are ordinarily treated by this method 
on account of the high price commanded by their low boiling-point dis- 
tillates. In this process the complex molecules are broken down into 
simpler ones upon subjecting them to a prolonged heating at temperatures 
at which they are unstable. 

(2) Steam Distillation, This is also termed the '' fractional " dis- 
tillation process and consists in introducing dry steam, termed " bottom 
steam " into the still, which assists in the vaporization of the volatile 
constituents and minimizes decomposition of the distillate and residue. 
Its action is based on the physical law that the boiling-point of a pair of 
non-miscible or slightly miscible liquids is lower than that of either pure 
component. The introduction of steam, therefore, serves to materially 
lower the boiling-point of the petroleum, and produces the maximum yield 
of heavy lubricating oils. It also tends to economize in fuel, and to shorten 



PETROLEUM ASPHALTS 



273 



the distillation process. The steam upon being dried by passing through a 
trap is introduced through perforated pipes at the bottom of the still, only 
when the temperature of the contents exceeds the boiling-point of water. 
Sometimes a partial vacuum is used in conjunction with steam to 
still further reduce the tendency towards cracking, thus increasing both 
the quantity and quality of the distillates, and reducing the duration of 
the process. This is based on the well-known physical law whereby the 
boiling-point of a liquid decreases with a reduction in atmospheric pressure. 




From "The American Petroleum Industry," by Bacon and Hamor. 

Fig. 107. — Tower System for Distilling Petroleum. 

Another modification consists in interposing a series of air-cooled 
" towers " between the still and the condenser. These act as dephlegma- 
tors, and result in a sharp separation of the various fractions, since the 
condensation which takes place in the towers washes the ascending vapors 
and purifies them. The vapors are conducted from the bottom of one 
tower to the top of the next, and so on, and separated into as many 
fractions as there are towers. This obviates the necessity of redistilling 
the fractions. The tower system is illustrated in Fig. 107. 

Continuous Distillation Processes. The continuous process was first 
perfected in Russia and is now being used very largely in the United 
States, particularly in the Gulf and California oil fields. 



274 ASPHALTS AND ALLIED SUBSTANCES 

Numerous methods have been suggested and tried for distilling petro- 
leums continuous!}^, only two of them, however, have come into use gen- 
erally, viz.: the "topping process" and the Livingston process. They 
reduce the cost of treatment, increase the output of the plant, and effect a 
sharper and cleaner fractioning of the distillates. Steam may or may 
not be used. 

(1) Topping Process. This is also known as the ^'skimming" process, 
the object of which is to distil the gasoline, naphtha, kerosene, and in 
certain cases the gas or fuel oil without, however, removing the lubricating 
oil. Most of the refineries in the California, Louisiana, Texas and Mexi- 
can fields do not produce lubricating oils on account of the inferior products 
derived from the respective petroleums. As a much more expensive 
equipment is required to manufacture lubricating oil, even when the 
crude does contain good lubricating fractions, refiners will often avail them- 
selves of the topping process to reduce the cost of equipment and plant. 

Various forms of topping plants are used, all operating in accordance 
with the principle employed for dehydrating petroleum by '' Heating under 
Pressure " (see p. 269). The oil is first passed through coils of pipe and 
heated under pressure in a furnace, and then allowed to expand into 
a vertical separating chamber where a suitable spreader causes it to flow 
downward over the walls in a thin film. The uncondensed vapors are with- 
drawn from the top and passed through a water condenser. The topped 
oil flows from the bottom into a heat exchanger where it transfers a good 
portion of the heat to the crude oil on its way to the furnace. The 
exchanger consists of pipes surrounded by wall-insulated pipes of larger 
diameter. The crude oil is passed through the inner pipes and the 
topped residuum through the outer ones. A typical illustration is shown 
in Pig. 108. 

The liquid to semi-liquid residuum obtained from the topping 
process is marketed under the names " asphaltum oil," " residual oil," 
'' fluxing oil " or " road oil," or if the distillation is carried further, the 
residue may become almost solid in consistency when cold, in which event 
live steam is introduced into the separating chamber to facilitate the 
removal of the volatile constituents and prevent the residue from becoming 
cracked and deteriorating in quality. 

(2) Livingston Process. This was perfected by Max Livingston of the 
Atlantic Refining Company, Philadelphia, the apparatus being illustrated 
in Fig. 109.^ It consists of eleven or more stills arranged side by side on 
a masonry foundation (36), with a separate fire chamber (12) underneath 
each still. The crude petroleum passes through the supply pipe (27) 

lU. S. Pat. 728,257, May 19, 1903. 



PETROLEUM ASPHALTS 



275 



into still No. 1 (on the left of the figure) which is provided with an 
internal steam coil (17) to precipitate any water and earthy matter carried 



I 



:^ao:^^iJ uiojj x!0 ^OH 






Q 



josuapuoQ o^ ioOe/^ 




xt 



by the oil. The vapors generated in this still are drawn off through the 
vapor pipe (16). 



276 



ASPHALTS AND ALLIED SUBSTANCES 



The oil freed from water and earthy matters then passes into still 
No. 2 (shown to the right of the first still), provided with a steam pipe 
(30) connected with a branch (31) leading to the bottom of the still to 
assist heating the oil, also with a series of fire flues (14) for the same pur- 
pose. Successive pairs of stills are alternately connected together at 
opposite ends by U-shaped connections (19), joined by elbows (20) to 
stand-pipes (21) inside the stills, the heights of which predetermine the 
liquid levels. Each stand-pipe (21) is surrounded by a sleeve (35) open 
at both ends, the upper end rising above the liquid, and the lower reaching 
a point near the bottom of the still. This device conveys the liquid 
from the bottom of the still into the following one. 




Fig. 109. — Livingston Apparatus for Continuous Distillation of Petroleum. 

The upper end of the stand-pipe (21) is brought to a slightly lower 
level in each succeeding still, so that the oil will flow by gravity through 
the entire series. The height in each stifl is adjusted to compensate for 
the diminution in the volume of its contents corresponding to the quantity 
of distillate removed. The vapor-space above the liquid in the series of 
stills increases as the distillation progresses and results in the production 
of purer distillates, due to a partial condensation of the higher boiling- 
point products, which wash the vapors in a manner similar to that which 
takes place in the '^ tower system " (p. 273). 

The vapors from each still are passed through separate condensers 
which recover fractions of uniform composition. The number of frac- 
tions depends upon the number of stills in use, the heavy residuum being 
withdrawn from the last one through the pipe (19). 

An ingenious series of pipes is provided so that in case any still needs 
repairing it can be temporarily cut off, and substituted with another. 

The process is readily controlled, economical to operate, and results 
in more uniform and better quality distillates. It is equally adaptable 



PETROLEUM ASPHALTS 277 

to the dry and steam distillation processes, also for distilling light fractions 
as well as heavy lubricating oils. 

Steam Distillation of Asphalt-bearing Petroleum. In practice, asphaltic 
petroleum is subjected either to the '' steam distillation process " (see 
p. 272) or to the " topping process " (see p. 274). The distillation is 
designed to separate: 

(1) Gasoline, naphtha, kerosene, and in some cases the gas or fuel 
oil, in which event the residuum will be of a liquid or semi-liquid consist- 
ency, designated " residual oil." 

(2) GasoHne, naphtha, kerosene, gas or fuel oil, and lubricating oil, 
in which event the residuum will be of a semi-solid to soUd consistency, 
designated " residual asphalt." 

The charge of petroleum is distilled until the residue attains the proper 
consistency, which is controlled by sampling the residue through pet- 
cocks set in the still, or by recording the temperature of the residue, or 
by observing the character of the distillate. The further the process is 
continued, the higher the fusing-point and the harder the consistency of 
the residue. The temperature of the residue at the termination of the 
process will vary between 600 and 750° F., and the time of distillation 
between twelve and thirty-six hours. When the distillation is completed, 
the residuum is run or blown into a closed cylindrical vessel constructed 
of steel, where it is allowed to cool until the temperature is reduced suf- 
ficiently to permit its being filled into barrels or drums without danger 
of igniting on coming in contact with air. 

Where the residue is distilled to a definite consistency without further 
treatment, the distillation is known as " straight running," and the 
residue a " straight run asphalt." In certain cases a portion or " fraction " 
of the distillate is mixed with the residue at the close of the distillation, 
which is termed '^ cutting back," the object of which is to modify the prop- 
erties of the residual product or to economically dispose of a fraction which 
otherwise has little value commercially. 

If the process of distillation is conducted too rapidly, or the tem- 
perature is permitted to rise too high, the residue " cracks " and becomes 
altered in composition, usually with the simultaneous formation of con- 
siderable carbonaceous matter. 

Table XXI shows an outline of the steam distillation process of treating 
asphalt-bearing petroleum, including the production of lubricating oil. 



278 



ASPHALTS AND ALLIED SUBSTANCES 







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280 ASPHALTS AND ALLIED SUBSTANCES 



The following products are obtained: 



Gasoline Of 60° Bauin^ 

Light naphtha ("No. 1 Tops") Of 55° Baume 

Heavy naphtha Of 50 and 45° Baume respectively 

Kerosene Ranging from 40 to 48° Baum6 

Gas or fuel oil, including a product marketed as "orchard heating oil," or "smudge 
oil," ranging from 26-28° Baume (burnt in orchards to prevent frost from dam- 
aging the trees), also a fuel oil of 27° Baum6, having a flash-point of 150° F. 

Lubricating oil Ranging from 17 to 25° Baume 

Residual asphalt Of varying hardness and fusing-point 

Road oil Varying in gravity from 20-18° Baum6 

The following yields are obtained from California asphaltic petroleum \^ 

Gasoline (60° Baum6) Trace-20% 

Naphtha (55° Baum6). . Trace-15% 

Kerosene (35-42° Baume) Trace-30% 

Gas or fuel oil (25-30° Baume) 10-40% 

Lubricating oil (17-25° Baume) 15-70% 

Residual asphalt 20-40% 

Loss 1- 4% 

Steam Distillation of Non-asphaltic and Mixed-base Petroleums. The 

object of this process is to avoid cracking, and obtain the maximum yield 
of lubricating oil. The stills are charged four-fifths full with the oil and 
the fires hghted. When the temperature reaches 280° F., all of the crude 
light naphtha has distilled off, whereupon steam is introduced through 
perforated pipes at the bottom, at first slowly, and then more rapidly as 
the distillation progresses. The procedure is shown diagrammatically in 
Table XXII, p. 278. 

The crude heavy naphthas have distilled off when the temperature 
reaches 330° F. (about 145° lower than when distilled dry), the crude kero- 
sene when the temperature reaches 500° F., (about 125° lower than when 
distilled dry), and the paraffine distillate when the temperature reaches 
620° F. At this point the distillation is stopped. In the case of non- 
asphaltic crude oil, the so-called '' cylinder stock " remains in the still, 
and with mixed-base crude, an asphaltic residue remains behind, which may 
either be marketed as such, or treated with air to produce a " blown as- 
phalt." 

The following yields are obtained: 





Non-asphaltic Petroleum. 


Mixed-base Petroleum. 


Crude light naphtha . ... 


10-15% 
10-12% 
35-50% 
15-25% 
8-15% 


8-13% 

8-13% 

20-35% 

20-30% 


Crude heavy naphtha 


Crude kerosene . 


Paraffine distillate . . 


Cylinder stock 


Residual asphalt 


15-20% 


Loss . . 


2- 4% 


2- 4% 







i"The American Petroleum Industry," by Bacon and Hamor, 1st edition, p. 503. 
2 Bulletin No. 32, California State Mining Bureau. 



PETROLEUM ASPHALTS 281 

Crude light naphtha, crude heavy naphtha, and crude kerosene are 
refined further by subjecting them to: 

(1) A second steam distillation. 

(2) A chemical treatment with sulphuric acid and caustic soda. 

The paraffine distillate is subjected to a second dry distillation to 
convert the paraffine into a crystalline form which may be filtered more 
readily. The distillate is then cooled to 20 or 25° F. and filter-pressed 
(see p. 307), to separate the so-called '' pressed oil " from the " slack 
wax." The pressed oil is then steam-distilled to separate the gas or fuel 
oil from the neutral oil stock, and the latter is again steam-distilled to frac- 
tion the various lubricating oils, which are finally purified with sulphuric 
acid and caustic soda. The slack wax is treated as described on p. 308. 
The cylinder stock obtained as a residue from non-asphaltic petroleum is 
first treated with sulphuric acid and caustic soda and then filtered through 
fuller's earth (a variety of clay obtained in Florida and Georgia, of fine 
texture and low specific gravity which has the property of retaining any 
dark-colored constituents). The distillate is forced through an upright 
cylinder having a perforated bottom, and holding 10 to 20 tons of the 
fuller's earth, under the combined influence of heat and pressure. 

The following commercial products are obtained by the steam distillation of 
non-asphaltic and mixed-base petroleums: 

Gasolines varying in gravity from 76-86° Baume; 

Deodorized Light Naphthas varying in gravity from 60-74° Baume, includ- 
ing: 
V. M. & P. Naphtha (Benzine) having a gravity of 63° Baume; 
Deodorized Heavy Naphthas varying in gravity from 54-58° Baume; 
Kerosenes varying in gravity from 54-38° Baume; including products of 
52° Baume and 130° F. fire test ("Export Oil"); 
49° Baume and 130° F. fire test; 
48° Baume and 155° F. fire test; 
47° Baume and 150° F. fire test: 
41-38° Baume ("Mineral Colza Oil"); etc. 
Gas or Fuel Oils ranging in gravity from 38-36 1° Baume; 
Lubricating Oils ranging in gravity from 30-32° Baume, including: 

the "non-viscous lubricating oils" (having a viscosity under 150 on the 
Saybolt "A" Viscosimeter), and the "viscous lubricating oils" (hav- 
ing a viscosity between 150 and '^40). 
Paraffine Waxes, including: 

"Yellow Crude Scale," "White Scale," and "Refined Wax." The fusing- 
points range from 110-130° F., and are ordinarily marketed in grades 
of 118-120° F., 122-124° F., 124-126° F., and 126-128° F. 
Refined Cylinder Oils for use in steam cylinders at high temperatures, ranging 
in flash-point from 540-630° F., with fire-points from 550-750° F. The 
higher the fire- and flash-points, the more valuable the oil. 



282 



ASPHALTS AND ALLIED SUBSTANCES 



Dry Distillation of Non-asphaltic and Mixed-base Petroleums. The 

object of the dry or '' cracking " distillation of petroleum is to increase the 
yield of the low boiling-point products, including the gasolines and naphthas. 
The distillation is carried on in the following manner: when the tem- 
perature of the oil in the still reaches 175 to 200° F., gaseous products are 
first evolved, followed by the " crude light naphtha," which continues 
to come over until the temperature in the still reaches about 320° F. At 
this temperature the " crude heavy naphtha " commences to distil and is 
fractioned until the temperature reaches 475° F. Then the crude kerosene 
commences to boil over, and is fractioned until the contents of the still 
reach 625° F. A large amount of " cracking " commences at this point, 
and the fires are accordingly moderated to slow down the distillation and 
accelerate the decomposition as much as possible. The " cracked " 
distillate is fractioned until the temperature in the still reaches 675 to 
700° F., whereupon the distillation is brought to a close. There remains 
a viscous dark-colored " residuum '' varying in gravity from 20 to 25° 
Baum^ which may either be marketed under the name of '' residual 
oil " or '' flux oil " or else distilled separately. The method of pro- 
cedure is illustrated in Table XXIII, p. 279. 

The crude light naphtha, crude heavy naphtha and crude kerosene 
are treated as described under the steam distillation process of non- 
asphaltic and mixed-base petroleums. The cracked distillate is steam- 
distilled, and the respective fractions purified with sulphuric acid and caus- 
tic soda, and the gasoline, kerosene and gas or fuel oil separated in the 
manner outlined in the table. 

When the residue is dry distilled in a separate still known as a ^' tar 
still," the operation is carried on as rapidly as possible to avoid unneces- 
sary cracking, and render the paraflfine crystalline. The paraffine distillate 
comes over first, followed by the wax tailings, until nothing but the coke 
remains in the still, which after cooling is removed with a pick and shovel. 
The paraffine distillate is treated in the same manner as described under the 
heading " Steam Distillation of Non-asphaltic and Mixed-base Petroleums." 

The following average yields are obtained : 





Non-asphaltic Petroleum. 


Mixed-base Petroleum. 


Crude light naphtha 


5 - 8% 

7 -10% 
40 -45%, 
25 -30% 
10 -12% 

5 - 6% 

8J- 9^ parts 

^ part 
1-2 parts 


6-8% 
13-15% 
16-18% 
20-25% 
40-50% 

4- 5% 

35-42 parts 
1- 2 parts 
4- 6 parts 


Crude heavy naphtha 

Crude kerosene 


Cracked distillate 


Residuum 


Loss 


Upon distillation of the residuum: 

Paraffine distillate 

W^ax tailings 


Coke 



PETROLEUM ASPHALTS 283 

The following represent the more important products obtained: 

GasoUnes and naphthas corresponding with those obtained from the steam 
distillation process. In addition, there are obtained a series of heavy- 
naphthas ranging in gravity from 56-50° Baume, used in the paint and 
varnish trades and for dry cleaning purposes, Hkewise a naphtha of 
48-50° Baume used by varnish manufacturers as a "turpentine sub- 
stitute." 

Kerosenes varj-ing from 52-36° Baimae. 

Gas or fuel oils varying from 40-28° Baum^. The gas oils derived from 
mixed-base petroleums have a gravity of 34-36° Baume. 

Lubricating oils similar to those obtained from the steam distillation process. 

Residuum ranging from 35-18° Baume. The residuum obtained from 
non-asphaltic petroleum varies from 21-22° Baume, and is used for 
laying dust ("road oils") and for fluxing harder asphalts. 

Paraffine wax of the same grades as obtained from the steam distillation 
process. 

We will now take up the asphalts derived from petroleum, which may be 
classified into four groups, viz.: residual oils, blown asphalts, residual 
asphalts and sludge asphalts. 



RESIDUAL OILS 

These are obtained in the following manner,^ viz.: 

(1) The dry distillation of non-asphaltic petroleum. 

(2) The dry or steam distillation of mixed-base petroleum. 

(3) The steam distillation of asphaltic petroleum. 

They are characterized by being liquid to semi-Hquid at room tem- 
perature (77° F.), having a fusing-point of less than 80° F. (K. and S. 
method) . 

The characteristics of the residual oil depend upon three factors, 
viz. : 

(1) The nature of the petroleum from which they are produced. 

(2) The extent to which the distillation has been carried. The smaller 
the amount of volatile constituents removed, the more liquid will be the 
residual oil. 

^ (3) The care with which they have been prepared. 

1 "Bituminous Materials for Use in and on Road Surfaces, and ^Means of Determining their 
Character," by Clifford Richardson, Proc. Am. Soc. Testing Materials, 9, 580, 1909; "The Modern 
Asphalt Pavement," by Clifford Richardson, New York, 1908; "Characteristics and Differentiation 
of Native Bitumens and their Residuals," by Clifford Richardson, Eng. Record, 67, 466, 1913; 
"Laboratory Manual of Bituminous Materials," by Pr6vost Hubbard, 1st edition, pp. 123-127, 
1916. 



284 ASPHALT AND ALLIED SUBSTANCES 

The character of the petroleum from which the residual oil has been 
produced is indicated by the percentage of solid paraffines contained in 
the residual oil and its specific gravity at 77° F., viz.: 





Specific Gravity 
at 77° F. (Test 7). 


Solid Paraffines 
(Test 33) 


Residual oils from non-asphaltic petroleum 

Residual oils from mixed-base petroleum 


0.85-0.95 
0.90-1.00 
0.95-1.02 


4.0- 15.0% 
Trace- 5.0% 
0.0- 0.25% 


Residual oils from asphaltic petroleum 





Residual oils derived from petroleum composed principally of paraffi- 
naceous hydrocarbons have the following disadvantages when used as fluxes: 

(1) They are apt to show a separation of solid paraffinaceous hydro- 
carbons at low temperatures, giving the oil a gritty appearance. 

(2) They do not flux with the hard asphalts and asphaltites as readily 
as the residual oils derived from petroleums containing a substantial 
amount of aromatic hydrocarbons. It should be noted that the residual 
oils derived from asphaltic petroleum constitute the best residual fluxes. 

(3) They are apt to show a separation of greasy matter (paraffine 
or vaseline-like bodies) after having been fluxed with hard asphalts 
(Test 3). 

Residual oils from non-asphaltic petroleum are not produced in 
large quantities to-day, as this character of petroleum is generally distilled 
to recover the lubricating oils and paraffine wax (see " Treatment of 
Residuum " in the dry distillation of non-asphaltic petroleum, p. 282). 

Residual oils from mixed-base petroleums may be divided into two 
classes, namely, those derived from mixed-base petroleums produced in 
the United States, and those derived from Mexican petroleum. The latter 
may be differentiated by a higher percentage of fixed carbon (about 10 
per cent vs. less than 5 per cent in the United States product), a smaller 
percentage of saturated hydrocarbons (less than 50 per cent vs. greater than 
50 per cent in the United States product), a larger percentage of sulphur 
(greater than 4 per cent vs. less than 2 per cent in the United States 
product) and a lesser solubility in 88° naphtha (about 80 per cent vs. greater 
than 90 per cent in the United States product). 

Residual oils derived from asphaltic petroleums may be divided 
into two classes, viz. those obtained from Trinidad petroleum, and those 
from United States asphaltic petroleums. The former is differentiated 
by a larger percentage of sulphur (greater than 2 per cent vs. less than 
2 per cent in the United States product). 

Another important criterion in arriving at the value of residual 



PETROLEUM ASPHALTS 285 

oil for certain purposes is the percentage of volatile constituents. The 
greater the percentage of volatile matter, the less durable it will be upon 
exposure to the weather. This is important when the residual oil is 
used to flux harder asphalts and asphaltites, in which event it is desirable 
that the volatile constituents shall not exceed 5 per cent at 500° F. in four 
hours (Test 16). Residual oils of this character will withstand exposure 
to the weather remarkably well, either when used alone or in various com- 
binations (as fluxes), and very much better than any of the tars. They 
are not as efficient in this respect, however, as the soft (non-volatile) 
fatty-acid pitches and vegetable and animal oils and fats. 

Residual oils in general comply with the following characteristics: 

(Test 1) Color in mass Brownish black to 

black 

(Test 2a) Homogc;neity to the eye at room temperature Uniform to gritty 

(Test 26) Homogeneity under the microscope Uniform to lumpy 

(Test 3) Appearance surface aged indoors Variable 

(Test 7) Specific gravity at 77° F 0.85-1.05 

(Test 8) Viscosity Variable 

(Test 9c) Consistency at 77° F 0-7 

(Test 10) Ductility Variable 

(Test 13) Odor on heating Oily 

(Test 15a) Fusing-point (K. and S. method) 0-80° F. 

(Test 156) Fusing-point (B. and R. method) 10-98° F. 

(Test 16) Volatile matter Variable 

(Test 17a) Flash-point 300-550° F. 

(Test 18) Burning-point 350-650° F. 

(Test 19) Fixed carbon 2-10% 

(Test 21a) Solubility in carbon disulphide 98-100% 

(Test 216) Non-mineral matter insoluble 0-^% 

(Test 21c) Mineral matter 0-^% 

(Test 22) Carbenes 0-1% 

(Test 23) Solubility in 88° naphtha 80-99% 

(Test 24) Solubility in other solvents . . Soluble in benzol 

and turpentine 
and partly sol- 
uble in alcohol 
and acetone 

(Test 25) Water 0-Tr. 

(Test 28) Sulphur Tr.- 5% 

(Test 30) Oxygen 0-3% 

(Test 33) Paraffine 0-15% 

(Test 34) Saturated hydrocarbons 30-90% 

(Test 35) Sulphonation residue 90-100% 

(Test 37) Saponifiable constituents Tr.- 5% 

(Test 40) Glycerol Absent 

(Test 41) Diazo reaction ; No 

(Test 42) Anthraquinone reaction No 

Table XXIV includes a few of the author's tests on typical residual oils. 

Residual oils are so soft and liquid that it is impossible to ascertain their hard- 
ness by the needle penetrometer (Test 96) or their fusing point by the cube method 
(Test 15c). The consistometer (Test 9c) and the viscosity test (Test 8a, b, c, d, e and 
/) are accordingly used for recording their liquidity, and and Kramer-Sarnow or the 
ball and ring methods for determining their fusing point. 

For a description of "road oils," see pp. 353-360. 



286 



ASPHALTS AND ALLIED SUBSTANCES 







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PETROLEUM ASPHALTS 287 

BLOWN PETROLEUM ASPHALTS 

These are manufactured from residual oils derived from asphaltic, 
mixed-base or non-asphaltic petroleums, by blowing with air at elevated 
temperatures. 

It has been recognized for many years that petroleum products become 
changed in their physical properties by treating with oxidizing agents 
or air. One of the first to report this was Gesner in 1865/ who 
remarked that 

"Organic substances are oxidized by the atmosphere, and its action promoted 
by a high temperature. Hot air has therefore been forced through hydrocarbon 
oil during the process of purification, and in some instances with advantage." 

In 1876 W. P. Jenney patented the process of treating sludge oil 
obtained in refining petroleum with sulphuric acid, with a current of air 
at a temperature of 250° C.^ He observed that a resinous substance was 
produced by the absorption of atmospheric oxygen by the oil. 

De Smedt patented a process for oxidizing coal tar with potassium 
permanganate or permanganic acid at a temperature of 300° F.,^ also 
the method of oxidizing petroleum residues in a similar manner.^ 

The first to manufacture blown asphalt on a commercial scale was 
F. X. Byerley, w^ho obtained a patent in 1894^ for blowing air through petro- 
leum residues (and specifically those derived from Lima, Ohio crude oil), at 
temperatures between 400 and 600° F. In this way he obtained '' pitches '^ 
of variable properties depending upon the temperature and the duration 
of the blowing process. For the softer grades (fusing under 200° F.), 
the Lima residuum was blown three days at 400° F., during which 2 per 
cent of distillate w^as produced. For the harder grades (fusing at about 
400° F.) the residuum was blow^n four to five days at 500° F., during which 
between 5 and 6 per cent of distillate was recovered. The product was 
claimed to be resistant to changes in atmospheric temperature, and to 
differ from the corresponding steam-distilled asphalt by being readily 
soluble in petroleum benzine or naphtha. Byerley marketed the product 
under the name of " byerlite." (See p. 18.) Air under a pressure of 
from 6 to 7 lb. per square inch was passed through a 6000-gal. still of the 
oil at the rate of 450 cu.ft. per minute. Ohio petroleum residue of 21 

i"A Practical Treatise on Coal, Petroleum and Other Distilled Oils," 2d Edition, 1865, p. 128. 
2U. S. Pats. 178,061 and 178,154, both of May 30, 1876. 

3 U. S. Pat. 236,995 of Jan. 25, 1881 to E. J. De Smedt. 

4 U. S. Pats. 237,662 of Feb. 8, 1881, and 239,466 of Mar. 29, 1881 to E. J. De Smedt; also 
Eng. Pat. of Feb. 28, 1881, No. 849 to J. H. Johnson. 

5U. S. Pat. 524,130, Aug. 7, 1894. 



288J ASPHALTS AND ALLIED SUBSTANCES 

to 27° Baume and Texas petroleum residue of 12 to 15° Baum^ were first 
used for the purpose.^ 

G. F. and G. C. K. Culmer obtained patents for a similar process,^ 
according to which petroleum residues of about 18° Baume mixed with re- 
fined Trinidad or other native asphalt, were heated to 193° C. and blown 
for forty hours. From 3000 to 6000 cu.ft. of air per hour were passed 
through a still containing 3i tons of the residue. After a time the external 
source of heat was removed, since it was found that the temperature of the 
mass increased of its own accord, due to the chemical changes induced 
by the introduction of air. The oxidation progressed very rapidly at 
first, and then more slowly, as it approached the end of the treatment. 
The loss in weight varied between 5 and 20 per cent. The product was 
claimed to be less brittle in winter, and less liable to soften under summer 
heat than asphalts derived from petroleum by straight distillation processes. 

J. A. Dubbs patented a process^ for treating petroleum residues to obtain 
asphalt, which consists in heating them to a temperature of 150 to 230° C. 
and blowing first with air alone, and then with air mixed with steam in vary- 
ing proportions, depending upon the consistency of the product desired. 

In the foregoing processes the apparatus is extremely simple, con- 
sisting essentially of a still as is used for distilling petroleum (Fig. 105), 
the air being introduced through a series of pipes at the bottom, so arranged 
as to direct it against the sides. 

According to modern practice, either air alone or a mixture of air and 
steam are blown through the " topped petroleum,'' i.e., petroleum from 
which the gasoline, naphtha and illuminating oils have been removed by 
prior distillation, at 525 to 575° F. for ten to twenty hours, or until the 
residue attains the desired consistency. It is found unnecessary to use 
any of the metallic oxidizing agents described in the earlier patents. With 
Mid-continental residual oils, the loss varies between 10 and 20 per 
cent and with California residual oils between 25 and 35 per cent,^ 
depending upon the fusing-point of the blown product. 

1 Byerley vs. The Sun Co., Circuit Court of the U. S. for the Eastern Dist. of Pennsylvania, 

Oct. Session, 1908, No. 201. See also U. S. Pat. 634,818 of Oct. 10, 1899 to J. W. Hayward. 

»U. S. Pats. 635,429 and 635,430 both of Oct. 24, 1899. 

»U. S. Pat. 1,057,227 of Mar. 25, 1913. 

^ In this case the distillate consists of a reddish oil about 21° Baum6, which on redistillation 
yields: 

Naphtha (45° B6.) 5% 

Kerosene (35° B6.) 10% 

Gas oil (28° B4.) 20% 

Light lubricating oil (23° B6.) 25% 

Heavy lubricating oil (19° B6.) 20% 

Black residuum , 15% 

Loss 6% 

Total 100%> 



PETROLEUM ASPHALTS 289 

Comparatively little is known regarding the exact chemical reactions 
which take place on blowing. Analysis shows that little oxygen actually 
combines with the asphalt.^ It seems to be fairly well established that the 
effect of blowing is to eliminate hydrogen, which unites with the oxygen 
of the air, forming water. The process is also manifested by a condensing 
action, whereby the hydrocarbons polymerize, forming bodies of higher 
molecular weight and more complex structure. 

Blown asphalts vary in consistency from semi-liquids to moderately 
hard solids at room temperature. They are marketed under various pro- 
prietary names such as Byerlite, Sarco, Hydrolene, Texaco, Parolite, 
Korite, Stanolite, S. 0. Binders, Obispo, Ebano, etc. 

The advantages of " blowing " over the steam distillation process are 
as follows : 

(1) The yield of asphaltic residue from the blowing process is much 
greater than when steam distilled. In actual practice, with a topped 
asphaltic crude, the yield of blown asphalt varies between 75 and 90 per 
cent. Of the balance, 20 to 8 per cent is recovered as distillate, and 5 to 
2 per cent represents loss. 

(2) Blown petroleum asphalts are less susceptible to temperature 
changes than steam distilled products, and in addition acquire a certain 
amount of elasticity and resilience, usually termed " rubber-like proper- 
ties." Comparing the respective asphalts of the same fusing-point and 
derived from the same crude, we find the blown product to be tougher, 
less brittle, softer in consistency and having a lower " susceptibility fac- 
tor " (see p. 501) than the steam distilled product. 

(3) In many cases it is possible by blowing to obtain a residue of better 
quality than if the steam distillation process were used, and in fact the 
blowing process renders many crude petroleums available which could not 
otherwise be used for preparing high fusing-point asphalts. Non-asphaltic 
petroleum will produce fairly good asphalts when blown, whereas the same 
crude will produce worthless residual asphalts by the steam distillation 
process. It is found that the more asphaltic the crude, the better the 
quality of the blown product, and the shorter the duration of the blowing 
process. Petroleums of mixed-base such as Mid-continental and certain 
of the Texas crudes, must be blown very much longer than pure asphaltic 
crudes, including the Cahfornia and Trinidad. 

(4) It is easier to control the " grade " of asphalt by blowing. As 
previously noted, the progress of blowing is more rapid at the start of the 
process than towards its conclusion. In other words, the residual asphalt 

1 "Petroleum Analytical Methods," by S. P. Sadtler, 8th Intern. Cong, of Applied Chem., 
25, 729-733, 1912. 



290 



ASPHALTS AND ALLIED SUBSTANCES 



is said to " come to grade " very slowly. With steam distillation, the alter- 
ation is much more marked at the end of the distillation process, so that 
the steam distilled asphalts " come to grade " very rapidly. In attempt- 
ing therefore, to produce a residual asphalt of a definite fusing-point or 



300 
260 
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|220 
^200 
^ 180 
f 160 
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12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 
Hours Blown 


\ 
































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8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 
Hours Blown 

From "Good Roads." 

Fig. 110. — Effect of Blowing on the Fusing-Point and Hardness of Petroleum Asphalt. 



hardness, the blowing process is preferable, since it may be controlled to 
better advantage. 

Fig. 110 shows the effect of prolonging the blowing process (at 425° F.) 
on the fusing-point (ball and ring method, Test 156), and penetration 
(needle penetrometer-test 96) of a topped mixed-base petroleum ^ 

1" Value of Blown Asphalts and their Manufacture," H. B. Pullar, Good Roads, 3, 146, 1912. 



PETROLEUM ASPHALTS 



291 



Fig. Ill illustrates the consistency, tensile strength (multiplied by 
10) and ductility curves of a typical blown petroleum asphalt produced 
from mid-continental petroleum, having a fusing-point of 127° F. (K. and 
S. method). 

The care with which blown asphalts are prepared largely influences 
their physical characteristics. When made from improper crudes or by 
careless treatment, blown asphalts are apt to have certain defects, viz. : 

(1) When made from non-asphaltic or mixed-base petroleums, they are 
likely to present a " greasy " surface, and especially on standing a few 
days, due to the partial separation of vaseline or paraffine-Hke bodies. 









32" 








r 


^* 






US' 














\ 


























LEGEND 

Tensile 
Strength {xio) 

Ductility 

© Fusing Fhinf 


90 
£0 
70 
60 
50 
AO 
•30. 
20 
10 
€ 






























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10 ZQ 30 40 50 60 70 fiO 90 100 110 120 130 140 150 160 

Temperature , Degrees ■Fohrenheit 
Fig. 111. — Chart of Physical Characteristics of Blown Petroleum Asphalt. 

This will be considered more fully in Chapter XXVIII (p. 485). 'Blown 
asphalts made from asphaltic crudes do not behave in this manner. 

(2) Blown asphalts, and especially those of high fusing-point, have the 
disadvantage of being " short," or in other words, they lack ductility. 
By carefully regulating the process, this defect may be minimized, particu- 
larly if the asphalt is subjected to a moderate amount of blowing. It is 
a fact, however, that the longer the blowing is continued, the less ductile 
will be the asphalt. 

(3) Asphalts when over-blown, or blown at too high a temperature, 
show a separation of non-mineral matter insoluble in carbon disulphide, 
and a large percentage of carbenes. The former may readily be detected 
under the microscope (see Test 25, p. 484), also in certain aggravated cases 
by the eye, by presenting a dull surfa^ce upon being disturbed (see Test 2a 
p. 484). 



292 APSHALTS AND ALLIED SUBSTANCES 

When the blown asphalts first appeared on the market, they unfor- 
tunately did not enjoy a good repute, but their quality has improved to 
such an extent that blown asphalts may now be procured of almost any 
fusing-point up to 300° F., which are not only more resistant to tempera- 
ture changes, but are at the same time as ductile as any unblown product 
of the same " grade " (i.e., fusing-point or hardness at 77° F.) 

In general, blown asphalts comply with the following characteristics: 

(Test 1) Color in mass Black 

(Test 2a) Homogeneity to the eye at room temperature . . Uniform to gritty 

(Test 26) Homogeneity under the microscope Uniform to lumpy 

(Test 3) Appearance surface aged indoors one week Bright to dull and greasy 

(Test 4) Fracture Soft grades do not show a 

fracture, hard grades 
present a conchoidal 
fracture 

(Test 5) Lustre Bright to dull 

(Test 6) Streak on porcelain Brownish black to black 

(Test 7) Specific gravity at 77° F 0.90-1.07. . 

(Test 9c) Consistency at 77° F 2-30 

(Test 9d) Susceptibility factor 8-40 

(Test 10) Ductility Variable 

(Test 11) Tensile strength Variable 

(Test 15a) Fusing-point (K. & S. method) 80-300° F. 

(Test 156) Fusing-point (Ball and Ring method) 100-325° F. 

(Test 16) Volatile matter, 500° F. in 4 hours 1-12% 

(Test 17a) Flash-point 350-550° F. 

(Test 18) Burning-point 400-650° F. 

(Test 19) Fixed carbon 5- 20% 

(Test 21a) Solubility in carbon disulphide 95-100% 

(Test 216) Non-mineral matter insoluble 0- 5% 

(Test 21c) Mineral matter 0- §% 

(Test 22) Carbenes 0-10% 

(Test 23) Solubility in 88° naphtha 50-90% 

(Test 24) Solubility in other solvents Largely soluble in turpen- 
tine and benzol, and 
slightly soluble in alco- 
hol and acetone. 

(Test 25) Water Absent 

(Test 28) Sulphur Tr.- 7.5% 

(Test 30) Oxygen 2- 5% 

(Test 33) Paraffine 0- 10% 

(Test 34) Saturated hydrocarbons 30- 75% 

(Test 35) Sulphonation residue 90-100% 

(Test 37) Saponifiable constituents Tr.- 2% 

(Test 40) Glycerol None 

(Test 41) Diazo reaction No 

(Test 42) Anthraquinone reaction No 

Fig. 112, plotted by the author from hundreds of determinations, 
shows the relation between the specific gravity and fusing-point of 
residual oils, blown asphalts and residual asphalts. 

Residual oils range in specific gravity from 0.85 to 1.07 at 77° F., 
and in fusing-point (K. and S. method) from to 80° F. ; blown asphalts 
range in specific gravity from 0.90 to 1.05, and in fusing point from 80 
to 300° F.; residual asphalts range in specific gravity from 1.00 to 1.17 



PETROLEUM ASPHALTS 



293 



and in fusing-point from 80 to 225° F. The chart shows that residual 
oils verge into the residual and blown asphalts respectively, and it also 
graphically illustrates the difference between the residual and blown 
asphalts. It will be observed that the effect of blowing is to increase the 
fusing-point and decrease the specific gravity of the product. 




0.85 



Fig. 112. 



80 100 200 

Fusing Point, Degrees Fah. 



ZZb 



500 



-Relation between the Specific Gravity and Fusing-Point of Residual Oils, 
Blown Petroleum Asphalts and Residual Asphalts. 

Another method for distinguishing between blown and residual asphalts, 
devised by the author, consists in finding their hardness by means of the 
consistometer (Test 9c) at a temperature exactly 50° F. lower than their 
fusing-point by the K. and S. method. Blown asphalts show a hardness of 
less than 15, whereas residual asphalts show a hardness greater than 
15 under these conditions. This is illustrated by the following examples: 





Fusing-point, 
(Test 15a). 


Hardness (Test 9c). at 

50° F. below the 

Fusing-point. 


Blown petroleum asphalts: 
Lima grade 120 . . . 


91.5° F. 
155 
214 
271.5 
100 
164 
215 

90 
108 
124 
146 
168.5 
209 
119.5 
158 


Hd. at 41.5° F.=11.2 
Hd. at 105.0° F. =10.1 
Hd. at 164.0° F. = 7.8 
Hd. at 221.5° F. = 6.7 
Hd. at 50.0° F. =11.9 
Hd. at 114.0° F. =10.3 
Hd. at 165.0° F. = 8.4 

Hd. at 40.0° F. =21.5 
Hd. at 58.0° F. =22.2 
Hd. at 74.0° F. =22.2 
Hd. at 96.0° F. =22.9 
Hd. at 118.5° F. =23.5 
Hd. at 159.0° F. =22.9 
Hd. at 69.5° F.=21.5 
Hd. at 108.0° F. =21.5 


" 250.. 


" " 185 . . 


" 285 


Mid-continental grade 115.. 

" 180.. 

" 215.. 
Residual asphalts: 
California grade E 


" DE 

" D 

" C 


" CB 

" B 


Mid-continental grade 140. . 
" 180.. 



294 ASPHALTS AND ALLIED SUBSTANCES 

It is of interest to note in connection with the foregoing figures, that 
for any particular crude, the hardness at the '' fusing-point less 50° F." 
decreases with the extent of the blowing, but remains practically constant 
in the case of the residual asphalts, regardless of the degree to which the 
distillation may have been carried. 

Upon comparing a residual asphalt with a blown product of the same 
fusing-point, it will be found that the latter is considerably softer, as 
evidenced by its consistency or penetration. Conversely, upon comparing 
a residual asphalt with a blown product of the same hardness or pene- 
tration, the fusing-point of the latter will be found to be considerably 
higher. It is also interesting to note that blown asphalts are more soluble 
in 88° naphtha (and in other petroleum distillates) than unblown residual 
asphalts of the same fusing-point. 

Blown asphalts, due to their greater softness, and correspondingly 
large proportion of " life-giving '' constituents, are better weather-resistants 
than residual asphalts derived from the same crude, having the same 
fusing-point and showing the same proportion of volatile matter. They 
are about equal in weather-resistance to residual asphalts of the same 
hardness prepared from the same crude, and far superior to sludge asphalts 
regardless of their hardness or fusing-point. It is a mooted question 
whether the native asphalts or the blown asphalts excel in weather- 
resisting properties, and to which in the author's opinion no categorical 
answer can be given. ^ 

Table XXV includes the results obtained by the author upon examining 
representative blown asphalts derived from different crudes and blown to 
different extents. 

SULPHURIZED ASPHALTS ^ 

Under the action of heat, sulphur has the same condensing effect on 
asphalt as oxygen. The sulphur eliminates hydrogen, in the form of 
gaseous hydrogen sulphide (H2S). This reaction may be roughly repre- 
sented as follows: 

CnH2n + S = CnH2n- 2 "f" H2S. 

The process of treating asphalt with sulphur was first disclosed by 
A. G. Day, ^ and subsequently by J. A. Dubbs/ who heated Pennsyl- 

i"The Modern Asphalt Pavement," loc. cit.; "Value of Blown Asphalts and Their Manufac- 
ture," by H. B. Pullar, Good Roads, 3, 146-7, 1912; "American Petroleum Industry," loc. cit. 
620-631. 

2 "The Effect of Sulphur on the Oxidation of Hydrocarbons, with Particular Reference to 
Asphalt," B. T. Brooks and I. W. Humphrey, J. Ind. Eng. Chem., 9, 746, 1917. 

" U. S. Pat. 58,615 of Oct. 9, 1866 to A. G. Day. 

4U. S. Pats. 468,867 of Feb. 16, 1892; 480,234 and 480,235, both of Aug. 2, 1892; also 608,372 
of Aug. 2, 1898 to J. A. Dubbs. 



.PAHLTIC 




0-Indiana 






Homo. 


Ho- 


*Jon-hom. 


Hoi 


Dull 
Conch. 


Bri 


Bright 




Black 
1.015 


Bk 
1 


14.1 





21.5 

41.9 

14.6 

2 

1 
0.125 


7. 
28. 
22. 
28. 
93. 

1 


0.75 
2.7 


0. 
1 


12.5 


13. 






190 . 
209 

2.1 
522 
10.3 


126 

144 

1. 

490 

15. 


- 




99.22 
0.68 


98. 


0.10 
0.4 
70.5 


0. 
0. 

84. 


- 




1 


7. 




1 




45 



TABLE XXV.— CHARACTERISTICS OF 



BLOWN PETROLEUM ASPHALTS 



' 






From 


NOK-..SP 






1 












From M 


...n-n„. 


P.™o.p 


... 


















Fnou 


A.re..r, 


Ps™„..„.. 




No. Test. 


1 


■- 1 








Mid-Continontal. 












Me„co. 






° 


nU. 






Ca, 


rornia. 




2<. 


Pkvncai CAaracimslics.- 


Homo. B 
Homo. i 


omo. Homo. Homo. Non-horn. Non-horn. 

.dull SI. dull Dull Dull DnU 

Conch. Conch. Conch. Conch. 

Bright Bright SI. dull SI. dull 

Black Black Black Black Black 
0.995 1.005 1.015 1.021 1.012 
5.85 9.8 14.1 18.3 18.7 

10.0 17.5 21.6 26.7 28.0 

1 25 0.125 0.0 o'.O 
0.10 0.50 0.75 1.80 2.70 


Non-hom. 

Non-hom. 

Dull 

Conch. 

BlLk 
1.002 

29!6 


Non-hom. 
Bright 


Mon-hom. 
Gritty 


Bright 
Bn.Bk. 

21 '.5 


Dnll^ 

'Black' 


\'on-hom. 
Bright"' 

Black' 
29^4 


Non-hom. 
Non-hom. 
Greasy 

0^985 
24^1 


Homo. 

Bt"gh^ 
Conch. 
Bright 

1.029 
20:0 


Homo. 
Gritty 

Conch. 
Bright 
Black 

10 ■ 6° 
17^7 

0:95 


Non-hom. 
Non-hom. 

Conch. 
SI. dull 
Black 

18:2 

1'^ 

3^20 


' Grit'tT' 
Greasy 

Dull ' 


Homo! 
Bn.Bk. 

80 


Homo!; 
Bright: 

's'lack'' 


Homo! 
Bright 

'Black' 
28.4 


Non-hom 
Conch. 

Black 


Homo. 
Homo. 
Bright 
Conch. 
Bright 
Black 

22.9 
61.3 




Homo. 
Non-hom 
Bright 

Brrght 
Black 

57^5 


Homo. 
Homo. 
Bright 

Black' 


Homo. 
Homo. 
Bright 
Conch. 
Bright 
Black 

3 


Homo. 
Homo. 
Bright 

Black' 


Homo. 
Homo. 
Bright 

'slack' 
5 


Homo. 

Br°i8ht 
Conch. 
Brigh' 

22 .'2 


Homo. 
Bright 
Conch. 
Bright 


Homo. 

Bright 
Conch. 
Bright 
Black 

GO. 4 


Homo. 




Bright 
Conch. 
Bright 

36!l 




9d 


Fnotuie 


Sl!eci5c' gravity at 77" F 


°0.9S7 
15.9 


28 



f 


ConjUtoncy at 32° F 






29.5 

o'.i" 




S""SIlS 'in c^Tt 77° F . 






























15a 
17a 


Fusing-pomt. dee. F., by K. & S. method.. 
Fuai-g-point. deg. F.. by B. & R. method. 
Volatile, 500" F. in 4 hn,., per cent 


91.5 


144 
3.25 


155 ^ 


522' 


52o' 


238 
12.5 


"^1 


50" 


164 

"10. 


4o 


4" 


'2.99 


1«'^ 


•ii 


i" 


236 


ir 


2.36 


104 


'€ 


15.7 


ir 


il 


116 


10.8 


I7 


155 


??l 


zl^ 


180.5 


•135'" 


Flash """^^^^'^-^^ ^^^^ 




22 


Solubility Tejls: 

Soluble in carbon disulphide S9 . 86 

Non-mineral matter insoluble "^ 


zz 


99.43 
0.45 


''^-.fs 


99.13 
1.25 


1:" 


0.22 


1:Io 


70.5 


o'.O 


'o'.so 


99.83 


sois 


'o:?o 


70:1 


"III 


98 


30 
8 


1 


f 


"III 


"o^so 


°0 28 


73A 


l;i 


li 


°lll 


0.22 


l:i 


l:i 


68.7 


Ir 


28 
35 


C/iemicl Te,u: 







68.0 




9^5 




74 '.7 







i:? 


If 


::":: 








51:3 


K 


3:2 


1 


.="..: 


.-.. 


..".. 






a 


1 


^L 






To face page I 


11' 


Pataffine 

Saturated hydrocarbons 

Sulphonation residue 







94. 



PETROLEUM ASPHALTS 295 

vania, Lima and Ohio residuums with 20 to 25 per cent of sulphur, at a 
temperature somewhat below the boiling-point of sulphur, until the evolu- 
tion of gas ceased. The resulting product is very similar in its physical 
properties to oxidized asphalt, being only slightly susceptible to tempera- 
ture changes, but it is still further lacking in ductility. Twenty years 
ago, asphalt treated in this manner w^as exploited under the name " Pitts- 
burg Flux.'- This was before blown asphalts appeared on the market, 
which on account of their smaller cost of production, soon displaced the 
sulphurized product. Other processes for vulcanizing asphalts were 
described by Peck.^ Callender vulcanized a mixture of Trinidad asphalt 
and fatty-acid pitch, ^ and William Griscom worked out a process along 
similar lines, producing a rubber-like substance by vulcanizing a mixture 
of fatty-acid pitch and asphalt.^ Mixtures of Grahamite and vegetable 
oils,^ coal tar pitch, ^ sludge asphalt,^ and wool-fat pitch ^ have also 
been vulcanized with sulphur to increase their elasticity and decrease their 
susceptibiHty to temperature changes. 

RESIDUAL ASPHALTS 

As stated previously, these are derived from the steam distillation 
of mixed base or asphaltic petroleums. Non-asphaltic petroleums are 
unsuitable for manufacturing residual asphalts. The distillation is con- 
tinued until the residual asphalt reaches the desired " grade." The 
temperature of the residue in the still is carefully observed, and imder 
no circumstances allowed to exceed 650 to 700° F., otherwise excessive 
decomposition and cracking of the hydrocarbons will take place, and 
result in the production of an inferior product. This is especially liable 
to be the case if a residual asphalt of hard consistency and high fusing- 
point is to be produced. Mexican petroleums are very susceptible to 
overheating, and great care must be taken not to allow the residue in 
the still to exceed a temperature of 560° F. In the early days of the 
industry, the residual asphalts were carelessly manufactured, without 
suitable temperature control, and as a result they soon fell into disre- 
pute. 

At the present time, residual asphalts are being marketed of excellent 
quality, including products fusing as high as 225° F., with a hardness in the 

1 U. S. Pats. 624,081 and 624,082 of May 2, 1899 to D. W. Peck. 
2Eng. Pat. of Oct. 11, 1881, No. 4408 to W. O. Callender. 

3 U. S. Pats. 529,727, 529,728, 529,729 and 529,730, dated Nov. 27, 1894 to William Griscom. 
< U. S. Pat. 210,405 of Dec. 3, 1878 to A. G. Day. 

5U. S. Pats. 403,548 of May 21, 1889 to B. E. Olseu and Chas. Gabriel; 598,147 of Feb. 1, 
1898 to Albert Hannemann, 

6 U. S. Pat. 651,358 of June 12, 1900 to J. A. Just. 
»Ger. Pat. 225,911 of May 25, 1907 tq A. F. Malchow. 



296 ASPHALTS AND ALLIED SUBSTANCES 

neighborhood of 100 on the consistometer scale (Test 9c), but this is due 
solely to the better methods of control. Other things being equal, it is 
not as easy to produce a residual asphalt as a blown product of a given 
high fusing-point. 

Lester Kirschbraun devised a process^ for removing undesirable constitu- 
ents of a paraffine- or vaseline-Uke character from residual asphalts (12 
to 24° Baume) derived from a mixed-base petroleum, by introducing large 
quantities of low-pressure steam superheated to 600 to 700° F., through 
a charge of the asphalt heated in a still to 450 to 700° F. It is claimed 
that these heavy paraffine- or vaseline-like hydrocarbons are non-cementi- 
tious, non-ductile, non-adhesive and greasy in character, and in addition, 
impart these undesirable characteristics to the asphaltic hydrocarbons 
when mixed with the latter. Kirschbraun 's product is supposed to have 
an unusual degree of ductility, in many cases capable of being elongated 
more than 100 times its cross-section at 77° F., also a high degree of ad- 
hesiveness and cementitiousness not found in residual asphalts distilled 
with saturated steam, or in blown asphalts prepared in the usual manner. 
Carelessly prepared residual asphalts may be detected by: 

(1) Lack of homogeneity (Test 2). This may be due either to over- 
heating or because the distillation has been continued too far. 

(2) The surface of the material assuming a *' greasy " appearance 
on aging. This is due to the use of crudes containing too large a propor- 
tion of paraffine- or vaseline-hke hydrocarbons, which have not been 
removed during the distillation process. 

(3) The presence of too large a percentage of volatile matter (Test 
16) or too low a flash-point (Test 17), due to the distillation not having 
been carried far enough, or at a temperature sufficiently high to remove 
the low-boiUng point constituents. 

(4) A large percentage of non-mineral matter insoluble in carbon 
disulphide (" free carbon ") (Test 216). This is due either to overheating 
or to the distillation having been carried too far. Carefully prepared 
residual asphalts should not contain more than 5 per cent. 

(5) The presence of carbenes (Test 22), which are produced by 
overheating. Carefully prepared residual asphalts should not contain 
more than 2 per cent. 

Residual asphalts made from mixed-base petroleum are not as sus- 
ceptible to overheating as those derived from purely asphaltic petroleum. 
In both cases the percentage of asphalt recovered in the distillation process 
is greater than that contained in the original petroleum, due to the fact 
that the heavy lubricating oils are polymerized or condensed under the in- 

» U. S. Pat. 1,194,750, Aug. 15, 1916, to Lester Kirschbraun. 



PETROLEUM ASPHALTS 297 

fluence of heat into substances resembling asphalt. In a purely asphaltic 
petroleum, the quantity of residual asphalt formed during the distillation 
process is proportionalely less than in the case of mixed-base petroleum, 
but the residual asphalt in the former case will not show a greasy surface 
on aging, no matter how carelessly it may have been distilled. 

Eesidual asphalts in general comply with the following characteristics: 

(Test 1) Color in mass Black 

(Test 2) Homogeneity Variable 

(Test 3) Appearance surface aged indoors 1 week . . Variable 

(Test 4) Fracture Conchoidal in the case of hard 

residual asphalts. 

(Test 5) Lustre Variable 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity at 77° F 1 . 00-1 . 17 

(Test 96) Penetration at 77° F 150-0 

(Test 9c) Consistency at 77° F 5-100 

(Test 9d) Susceptibility factor 40-60 

(Test 10) Ductility at 77° F Variable 

(Test 11) Tensile strength at 77° F 0.5-10.0 

(Test 13) Odor on heating Oily 

(Test 14o) Behavior on melting Pass rapidly from the solid to 

the liquid state 

(Test 15a) Fusing-point (K. & S. method) 80-225° F. 

(Test 156) Fusing-point (B. & R. method) 100-250° F. 

(Test 16) Volatile matter Variable 

(Test 17) Flash-point 400-600° F. 

(Test 18) Burning-point 450-700° F. 

(Test 19) Fixed carbon 5-40% 

(Test 21a) Soluble in carbon disulphide 85-100% 

(Test 216) Non-mineral matter insoluble 0- 15% 

(Test 21c) Mineral matter 0- 1% 

(Test 22) Carbenes 0- 30% 

(Test 23) Solubility in 88° naphtha 25-85% 

(Test 24) Solubility in other solvents Quite soluble in benzol and tur- 
pentine and scarcely soluble 
in alcohol and acetone 

(Test 25) Water None 

(Test 26) Carbon 85- 87% 

(Test 27) Hydrogen 9- 13% 

(Test 28) Sulphur Tr.- 10% 

(Test 29) Nitrogen Tr.- 1.0% 

(Test 30) Oxygen 0- 2^% 

(Test 32) Naphthalene None 

(Test 33) Paraffine O- 5% 

(Test 34) Saturated hydrocarbons 25- 75% 

(Test 35) Sulphonation residue 90-100% 

(Test 37) Saponifiable constituents 0- 2% 

(Test 41) Diazo reaction No 

(Test 42) Anthraquinone reaction No 

Residual asphalts are characterized by the following features: 

(1) Their comparatively high specific gravity, serving to distinguish 
them from blown asphalts. 

(2) Their greater hardness or consistency at 77° F. for a given fusing- 
point, which also distinguishes them from blown asphalts. 



298 ASPHALTS AND ALLIED SUBSTANCES 

(3) The greater tensile strength at 77° F. for a given fusing-point, 
which similarly distinguishes them from blown asphalts. 

(4) The fusing-point, which is lower, and serves to distinguish them 
from the asphaltites. 

(5) The susceptibiHty factor, which is very much higher than blown 
asphalts. In the case of residual asphalts the susceptibility factor is 
greater than 40, whereas with blown asphalts it is less than 40. 

(6) The volatile matter, which for a given fusing-point is lower than 
that contained in the crude native asphalts. 

(7) The flash-point, which for a given fusing-point is higher than that 
of the crude native asphalts. 

(8) The fixed carbon, which for a given fusing-point is greater than 
that of blown asphalts. 

(9) The mineral matter, which runs well within 1 per cent and serves 
to distinguish residual asphalts from most of the native asphalts. 

(10) Carbenes, when present in percentages in excess of 5, serve to 
distinguish them from native asphalts. 

(11) Paraffine when present serves to distinguish residual asphalts 
from native asphalts, although this test is not infallible, for as pointed out 
previously, there are certain residual asphalts which do not contain paraffine 
(i. e., obtained from asphaltic petroleums). 

(12) The saturated hydrocarbons will exceed 25 per cent in the case 
of residual and blown asphalts, whereas they will be less than 25 per 
cent in the case of native asphalts.^ With asphaltites the saturated hydro- 
carbons amount to less than 10 per cent. 

(13) A greater percentage of sulphonation residue is derived from 
residual and blown asphalts than from the various pitches.^ 

(14) A negative diazo reaction, which distinguishes residual asphalts 
from pitches derived from wood, peat, lignite, coal, shale and bones. 

(15) The absence of the anthraquinone reaction, which distinguishes 
residual asphalts from the various pitches derived from coal. 

(16) By the percentage of free asphaltous acids (Test 38a) which 
runs below 2J per cent in residual asphalts and above 2i per cent in the 
native asphalts. Similarly, the percentage of asphaltous-acid anhydrides 
(Test 386) runs less than 1§ per cent in residual asphalts and greater than 
IJ per cent in native asphalts. 

There has been much discussion whether or not it is possible to distinguish 
between petroleum asphalts and native asphalts. 2 Various methods have been 

»" Characteristics and Differentiation of Native Bitumens and their Residuals," by Clifford 
Richardson, Eng. Record, 67, 466, 1913. 

2 "Distinction of Natural Asphalt Bitumen from Petroleum Pitch and Coal-tar Pitch," by 
Jeno Kovdcs and S. S6b6t, Chem. Rev. Fett-Harz-Ind., 7, 8, 1900; "Detection of Adulterants 



PETROLEUM ASPHALTS 299 

proposed for the purpose, but the only ones which seem to give dependable results 
are the percentages of saturated hydrocarbons (Test 34), free asphaltous acids 
(Test 38a) and asphaltous-acid anhydrides (Test 386), referred to in items (12) 
and (16) above. 

At the present time it is impossible to distinguish between blown 
asphalts, and combinations of asphaltites with residual oils or soft 
residual asphalts, since their respective properties are very much alike. 

Residual asphalts obtained from California petroleum are customarily 
designated by letters to differentiate the different grades. The so-called 
'' A " grade is extremely hard and brittle and grinds to a non-adherent 
powder between the teeth, ranging in penetration between 5 and 20 
at 77° F. (No. 2 needle, 100 grams, 5 seconds). *' B " grade is quite 
hard and brittle and grinds to an adherent powder between the teeth, 
ranging in penetration between 15 and 50 at 77° F. '' C " grade chews 
with difficulty and ranges in penetration between 25 and 75 at 77° F. 
'* D " grade chews readily without sticking to the teeth, and ranges in 
penetration from 45 to 150 at 77° F. '' E " grade sticks to the teeth on 
chewing and shows a penetration greater than 200 at 77° F. '' F " and 
" G " grades are in reality residual oils of high and low viscosities 
respectively. When carefully prepared, " B " grade does not contain more 
than 2 per cent of non-mineral matter insoluble in carbon disulphide, 
and the softer grades correspondingly less.^ 

Fig. 113 shows the hardness, tensile strength (multiplied by 10) and ductility 
curves of a typical sample of "D" grade California residual asphalt fusing at 
124° F. (K. and S. method). 

Table XXVI includes the results obtained by the author on representative specimens 
of residual asphalts. 

in Natural Asphaltum," by B. Malenkovic, Oesterr. Chem. Zeit., 8, 123, 1905; "Distinction between 
Natural and Petroleum Asphalts," by J. Marcusson and R. Eichniann, Chem. Zeit., 32, 965, 1908; 
"Identifying Asphalts," by J. Marcusson, Chem. Rev. Fett-Harz-Ind., 18, 47, 1911; "Petroleum 
Asphalts," by D. Lohmann, Chem. Rev. Fett-Harz-Ind., 18, 107, 1911; "Chemical Composition 
and Methods of Distinguishing Natural and Artificial Asphalts," by J. Marcuason, Chem. Rev. 
Fett-Harz-Ind., 19, 166, 1912; "Separation of Natural and Petroleum Asphalts," by J. Marcusson, 
Chem. Zeit., 36, 801, 1912; Richardson's "Modern Asphalt Pavement," loc. cit., p. 276; "Quan- 
titative Determination of Natural Asphaltum in the Presence of Artificial Asphaltum," by J. 
Marcusson, Z. angew. Chem., 26, 91, 1913; "Detection of Natural Asphalt and Petroleum Pitch," 
by F. Schwarz, Chem. Rev. Fett-Harz-Ind., 20, 28, 1913; "Analysis of Petroleum Oil and Mineral 
Wax," by H. Kantorowicz, Chem. Zeit., 37, 1394, 1438, 1565, and 1594, 1913; "Differentiation 
of Natural and Artificial Asphalts," by J. Marcusson, Mitt. k. Materialprilf. 32, 419, 1914 
"Differentiation of Natural and Oil Asphalts," by E. C. Pailler, J. Ind. Eng. Chem., 6, 286, 1914 
"Chemistry and Analysis of Asphaltum," by J. Marcusson, Chem. Zeit., 38, 813 and 822, 1914 
"Chemical Composition of Natural Asphalts," by J. Marcusson, Z. angew. Chem., 29, 346 and 
349, 1916. 

i"The California Asphaltum Industry," by F. H. Minard, Eng. Mining J., 503, 1903; "Pro- 
duction and Use of Petroleum in California," Bulletin No. 32, California State Mining Bureau, 
San Francisco, Cal., Mar., 1904. 



300 



ASPHALTS AND ALLIED SUBSTANCES 

TABLE XXVI.— CHARACTERISTICS OF 



Test, 



Physical Characteristics 
Homogeneity to eye at 77° F. . . 
Homogeneity under microscope. . 
Appearance surface aged 7 days. 

Fracture 

Lustre 

Streak 

Specific gravity at 77° F ...... . 

Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

Susceptibility factor 

Ductility in cm. at 115° F 

Ductility in cm. at 77° F 

Ductility in cm. at 32° F 

Tensile strength in kg. at 115° F. 
Tensile strength in kg. at 77° F. . 
Tensile strength in kg. at 32° F. . 



Heat Tests 
Fusing-point, deg. F., by K. and 

S. method 

Fusing-point, deg. F., by B. and 

R. method 

Volatile, 500° F., in 4 hrs., 

per cent 

Flash-point, deg. F 

Fixed carbon, per cent 



Solubility Tests 
Soluble in carbon disulphide. , 
Non mineral-matter insoluble. 

Mineral matter 

Carbenes 

Soluble in 88° naphtha 



Chemical Tests 

Sulphur 

Paraffine 

Saturated hydrocarbons . 
Sulphonation residue. . . 



Feom Mixed-base Petro 



Mid-continental (Texas). 



Homo. 

Homo. 

Dull 



Bn. Bk 

1.032 

1.6 

7.2 
45.2 
44.8 
14.5 
55 


0.05 

1.0 

6.0 



97.5 

115 

0.92 
508 
8.1 



99.56 
0.22 
0.22 
0.8 

86.1 



1.2 

1.4 

42.0 



Homo. 
Homo. 

Dull 
Co-.ch. 

Bright 

Black 

1.050 

5.1 
15.2 
66.9 
51.7 
37 
19 


0.10 

2.7 
15.0 



119.5 

131.5 

0.78 
525 
13.8 



99.25 
0.50 
0.25 
1.8 

82.5 



0.95 
1.3 



Homo. 
Homo. 

Dull 
Conch. 
Bright 

Black 

1.078 

9.6 
23.5 
81.4 



9.5 



142 

159 

0.50 
532 
18.5 



99.03 
0.70 
0.27 
3.0 

80.3 



1.25 
60.7 
95.0 



Homo. 

Homo. 

Dull 
Conch. 

Bright 

Black 

1.095 
14.6 
42.2 
92.8 
49.5 
22 

2.5 


1.10 

7.0 

8.5 



158 

170 

0.78 
545 
22.7 



98.60 
1.08 
0.32 
3.7 

77.0 



1.0 



Homo. 
Homo. 

Dull 
Conch. 
Bright 

Black 
1.119 

27.1 

58.5 
107.0 

48.0 

12 



2.00 

6.0 

7.0 



167 

184 

1.00 
575 
23.1 



96.45 
3.12 
0.43 
5.0 

72.3 



1.3 

0.8 



Homo. 
Gritty 

Dull 
Conch. 
SI. Dull 

Black 

1.138 
40.2 
76.1 
>100 

>45 




4.50 

4.5 

5.5 



194 

213 

0.89 
590 
27.2 



94.07 
5.31 
0.62 
6.1 

64.7 



0.7 



Non-ho. 
Lumpy 

Dull 
Conch. 
SI. Dull 

Black 

1.145 
47.9 
38.8 
>100 

>45 




5.50 

4.0 

5.0 



205 

227 

0.71 
595 
33.3 



91.02 
8.20 
0.78 
12.3 
61.0 



0.6 

0.5 

70.1 



Residual asphalts obtained from the Texan mixed-base petroleum are 
characterized by the presence of paraffine, less than 1| per cent of sulphur 
and between 40 and 70 per cent of saturated hydrocarbons; those obtained 
from California asphaltic petroleum are practically free from paraffine, 
contain less than Ij per cent of sulphur, and between 25 and 40 per cent 
of saturated hydrocarbons; those derived from Mexican mixed-base 



PETROLEUiM ASPHALTS 



301 



TYPICAL RESIDUAL ASPHALTS 



LEU.M. 










From Asphaltic Petroleum. 






Mexican. 


California. 


Trinidad. 


Homo. 


Homo. 


Homo. 


Homo. 


Homo. 


Homo. 


Homo. 


Homo. 


Homo. 


Non-ho. 


Homo. 


Homo. 


Gritty 


Homo. 


Gritty 


Homo. 


Homo. 


Homo. 


Homo. 


Homo. 


Gritty 


Lumpy 


Homo. 


Homo. 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Conch. 


Conch. 


Conch. 






Conch. 


Conch. 


Conch. 


Conch. 


Conch. 




Conch. 


Bright 


Brig'it 


Bright 






Bright 


Bright 


Bright 


Bright 


Bright 




Bright 


Black 


Black 


Black 


Bn. 


Bn. Bk 


Black 


Black 


Black 


Black 


Black 


Black 


Black 


1.015 


1.021 


1.036 


1.031 


1.043 


1.065 


1.095 


1.113 


1.127 


1.158 


1.095 


1.120 


3.1 


4.5 


6.5 


2.7 


3.4 


6.8 


13.9 


28.8 


38.0 


45.1 


8.8 


27.2 


17.2 


21.5 


22.9 


7.0 


18.2 


21.5 


29.0 


63.0 


89.2 


98.0 


24.0 


70.2 


60.4 


)S.0 


^3.0 


45.8 


55.4 


64.6 


78.3 


>100 


>100 


>100 


58.7 


>1C0 


47.3 


17.8 


13.5 


48.0 


47.2 


46.6 


44.0 


> 42 


> 40 


> 45 


43.3 


> 45 


45 


12.5 


13.5 


31 


40 


57 


12.5 


8.0 








70 


3.5 


8 


3.5 


3 


75 


98.5 


9 


1 











22 









































0.4 


0.8 


0.75 


0.15 


0.25 


0.60 


1.65 


3.95 


3.40 


4.25 


0.4 


4.85 


2.8 


4.0 


5.0 


0.55 


1.1 


3.5 


6.2 


5.0 


4.0 


4.2 


2.8 


5.5 


8.5 


11.0 


10.5 


7.5 


8.5 


10.0 


12.0 


8.0 


5.2 


3.7 


8.7 


10.2 


121 


133 


143 


90 


108 


124 


146 


168.5 


209 


218 


115 


187 


141.5 


154 


162 


105 


129 


142 


163 


188 


220 


229.5 


132 


210 


0.76 


0.50 


0.47 


5.20 


3.40 


3.08 


2.44 


3.9C 


3.72 


2.12 


3.08 


2.75 


520 


555 


547 


450 


492 


500 


525 


535 


545 


563 


528 


561 


28.9 


30.6 


32.3 


12.0 


20.1 


24.8 


30.2 


34.0 


37.0 


39.7 


29.1 


38.4 


97.50 


98.22 


97.95 


99.80 


99.25 


98.93 


98.67 


98.64 


98.12 


86.20 


99.35 


98.39 


2.15 


1.33 


1.80 


0.05 


0.50 


1.07 


0.90 


1.10 


1.60 


13.48 


0.48 


1.28 


0.35 


0.45 


0.25 


0.15 


0.25 


0.30 


0.43 


0.26 


0.28 


0.32 


0.17 


0.33 


0.6 


1.82 


2.2 


0.5 


1.0 


1.5 


2.5 


4.2 


5.6 


28.2 


0.3 


0.8 


76.8 


68.9 


62.0 


82.5 


77.0 


71.2 


64.1 


52.3 


45.2 


35.7 


78.0 


66.6 


6.4 


4.2 


5.8 


0.9 




1.2 


1.4 




0.8 




2.8 


2.2 


2.6 


1.7 


1.4 


0.2 


0.1 


Tr. 


Tr. 


0.0 


0.0 


0.0 


0.0 


0.0 


38.5 


42.9 


30.3 


22.2 






30.6 




35.8 


37.0 


24.0 


28.3 


97.5 






92.5 










98.0 






96.4 



petroleum contain paraffine, between 4 and 8 per cent of sulphur and 
between 30 and 50 per cent of saturated hydrocarbons. In distilHng 
Mexican petroleum, it is necessary to use a large supply of steam to drive 
off as much sulphur as possible, and increase the ductihty of the residual 
asphalt, as the sulphur adheres unusually tenaciously to the hydro- 
carbons, including even the distillates. Residual asphalts obtained from 



302 



ASPHALTS AND ALLIED SUBSTANCES 



Trinidad asphaltic petroleums are practically free from paraffine, con- 
tain more than IJ per cent of sulphur, and 25 to 35 per cent of saturated 
hydrocarbons. < 

The weather-resisting property of residual asphalts varies, depending 
upon the following circumstances: 

(1) The crude petroleum from which they were derived. Other things 
being equal, asphaltic petroleum produces the most weather-resisting 
residues, mixed-base petroleum comes next, and non-asphaltic petroleum 
produces residuals having the least weather resistance. 



5Z' 



77' 



100 
90 
80 
70 
60 
50 
40 
30 
20 
10 




\ 






100 












' 








LEGEIND 


n 


\ 








N 
















Tensile 
Strength (x/dj 

Ductility 

Fusing Point 


/ 


'\ 








\ 
\ 


















\ 






\ 


















\ 

64.6 


\ 




\ 
v 




















\ 


s. 




\ 
\ 








57 
/ 


V 




















\ 


V 


\ 
\ 








/ 




\ 
\ 




















\ 


s 


55J 


, 




/ 




\ 






















X 


N 


Ik 
4 


/ 








\ 
























V 

/ 


N 


h^V 






\ 


\ 












]p 




__ — 


.--'' 


"1' 


? 




i 


k 


S3^ 


\, 


■^^ 


____ 



10 20 30 40 50 60 70 60 90 tOO IfO J20 130 140 150 160 

Temperature, Degrees Fahrenheit 
Fig. 113. — Chart of Physical Characteristics of D-Grade CaUfornia Asphalt. 



(2) The care with which the distillation has been performed. If the 
residue is badly decomposed or " cracked " as evidenced by the presence 
of free carbon or carbenes, its weather-resisting properties will suffer in 
proportion. 

(3) The extent to which the distillation has been carried. Soft grades 
of residual asphalt carrying a large percentage of oily constituents (Test 
38e), will stand the weather better than those from which the oily con- 
stituents have been removed by driving the distillation to a point where 
a hard and brittle residual asphalt remains. 

In general, residual asphalts of the highest quality are inferior in 
weather-resisting properties to native asphalts, blown asphalts, wurtzilite 
asphalts and fatty-acid pitches, upon comparing respective products of 
the same fusing-point and volatility. They are superior, however, to 



PETROLEUM ASPHALTS 



303 



corresponding sludge asphalts and pitches derived from rosin, wood, 
peat, lignite, coal and bones. 

SLUDGE ASPHALTS 



Sludge asphalts are produced in much smaller quantities than 
residual or blown asphalts. They are derived from the purification 
of various petroleum distillates by means of sulphuric acid (p. 278). 
The crude naphtha, kerosene and lubricating oils are treated in this 
manner in the form of apparatus known as an " agitator," illustrated 
diagrammatically in Fig. 114, consisting of a cyhndrical vessel A with a 
conical bottom and dome-shaped top B, 
holding up to 2400 barrels of the distil- 
late to be treated. The agitator is lined 
with lead containing about 6 per cent of 
antimony. The distillate is introduced 
through the pipe D, the acid or caustic 
soda through the pipe H, and the air for 
agitating the mixture through the line E. 
Pipe C is attached to a swivel so that it 
may be raised or lowered by a chain J, 
and serves to draw off the purified oil. 
The sludge is removed through the valve 
F, and G represents the acid tank. 

Naphtha is purified with 2 to 4 lb. of 
commercial sulphuric acid (66° Baume) 
per barrel of 50 gal. (about 0.5 per cent 
by volume), and agitated for half an 
hour. The acid after being allowed to settle is drawn off and constitutes 
the '' sludge." The distillate is next washed with water, introduced 
through the pipe F, then made alkaline with caustic soda solution (4 to 
10° Baume) and finally washed with water until it is neutral. 

Crude kerosene is treated in a similar maner. It is first agitated 
with 5 to 10 lb. of sulphuric acid (66° Baume) per barrel of 50 gal. (equiva- 
lent to about 1.5 per cent by volume) for one-half hour. The acid settles 
in three to five hours, when the '' sludge " is drawn off. The kerosene is 
next washed with water, then with a 4 to 10° Baume solution of caustic 
soda and finally with water until it is neutral. 

Crude lubricating oil is similarly agitated with 20 to 50 lb. of sulphuric 
acid (66° Baume) per barrel of 50 gal. (equivalent to about 3 per cent 
by volume) for one to two hours, and allowed to settle from four to six 




Fig. 114. — Apparatus for the Acid- 
Purification of Petroleum Dis- 
tillates. 



304 ASPHALTS AND ALLIED SUBSTANCES 

hours. The greater the percentage of acid used, the Ughter will be the 
color of the refined lubricating oil. The stock is then washed with water, 
transferred to a '' lye agitator," treated with caustic soda (1 to 6° Baume) 
until it becomes alkaline, and finally washed with hot water until neutral. 

The so-called '^ sludge asphalt " is present in the sulphuric acid sludge, 
which on cooling forms a black viscous mass. No asphalts are obtained 
from the caustic soda washings in the case of petroleum refining. The 
alkali is merely used to neutralize the sulphuric acid retained mechanically 
by the oil, thus differing from its action in the refining of peat and lignite 
tars. (See p. 214.) 

The acid sludges obtained from the purification of naphtha, kerosene 
and lubricating oil are combined and treated according to the process of 
John L. Gray.^ The sludge is digested with water, air and steam in a lead- 
lined receptacle, whereupon the lighter oily constituents rise to the surface, 
a heavy residuum settles to the bottom, and the acid passes into the 
aqueous layer. The lighter oils are withdrawn and the boiling continued 
until all the acid separates. The residuum is then washed with water, 
and heated by a spray of superheated steam until it is converted into 
sludge asphalt. The further the distillation is continued, the greater the 
fusing-point and hardness of the sludge asphalt. The recovered oil is 
known as the '^ acid oil distillate." The dilute sulphuric acid (specific 
gravity of 30 to 50° Baume) is concentrated, first in leaden pans, and 
finally in an iron still until it attains a gravity of 66° Baume, when it is used 
over again. 

Sludge asphalt tests as follows: 

(Test 1) Color in mass Black 

(Test 2a) Homogeneity to the eye at room temperature Uniform 

(Test 26) Homogeneity under microscope Variable 

(Test 3) Appearance surface aged indoors one week Bright 

(Test 4) Fracture Conchoidal 

(Test 5) Lustre Bright 

(Test 6) Streak on porcelain Black 

(Test 7) Specific gravity at 77° F 1 . 05-1 . 20 

(Test 96) Penetration at 77° F 150- 

(Test 9c) Consistency at 77° F 5-100 

(Test 9d) Susceptibility factor 40- 60 

(Teat 10) Ductility at 77° F 

(Test 13) Oder on heating Oily; similar to resid- 
ual asphalt 

(Test 14a) Behavior on melting Passes rapidly from 

the solid to the liq- 
uid state 

(Test 15a) Fusing-point (K. & S. method) 80-225° F. 

(Test 156) Fusing-point (B. & R. method) 100-250° F. 

(Test 16a) Volatile matter 500° F. in 4 hours 2- 20% 

lU. S. Pats. 923,427, 923,428, and 923,429, dated Jun. 1, 1909 to J. L. Gray; also 564,975 of 
Aug. 4, 1869, to Richard Dean. 



PETROLEUM ASPHALTS 305 

(Test 17o) Flash-point 300-500° F. 

(Test 19) Fixed carbon 5- 30% 

(Test 21a) Solubility in carbon disulphide 95-100% 

(Test 216) Non-mineral matter insoluble 0- 5% 

(Test 21c) Mineral matter i 0- 1% 

(Test 22) Carbenes -15% 

(Test 23) Solubility in 88° naphtha GO- 95% 

(Test 28) Sulphur 5- 10% 

(Test 30) Oxygen 3- 7% 

(Test 33) Paraffine 0- i% 

(Test 34) Saturated hydrocarbons Less than 10% 

(Test 35) Sulphonation residue 80- 95% 

(Test 37) Saponifiable constituents 0- 2% 

(Test 38a) Free asphaltous acids Less than 2% 

(Test 386) Asphaltous-acid anhydrides Less than 23% 

(Test 41) Diazo reaction No 

(Test 42) Anthraquinone reaction No 

Sludge asphalts are characterized by the following features: 

(1) Their intense black streak. 

(2) Their high susceptibility factor which distinguishes them from 
blown asphalts. 

(3) The high percentage of sulphur. 

(4) The high percentage of oxygen, which distinguishes them from all 
other forms of asphalt and constitutes one of the most dependable tests 
for identifying sludge asphalts. 

(5) The very small percentage of paraffine which distinguishes them 
from residual asphalts obtained from mixed-base petroleum. 

(6) The extremely small percentage of saturated hydrocarbons which 
serves to differentiate sludge asphalts from all other asphaltic products. 

(7) The comparatively large percentage of sulphonation residue which 
distinguishes them from pitches. 

(8) The negative diazo and anthraquinone reactions which distinguish 
them from pitches derived from wood, peat, lignite, coal, shales and bones. 

(9) The large solubility of the harder grades in 88° naphtha, which 
distinguishes them from residual asphalts of the same hardness and fusing- 
point. 

Attempts have been made to blow sludge asphalts, but without suc- 
cess, as the blowing process merely serves to harden them, without appre- 
ciably lowering their susceptibility factor. 

Typical samples of sludge asphalt examined by the author gave the 
results included in Table XXVII, p. 306. 

Sludge asphalts do not withstand the action of the weather as well as 
native asphalts, blown asphalts, residual asphalts, wurtzilite asphalt or 

1 Sludge asphalts all carry traces of lead, derived from the leaden vessels in which they are produced, 
which is carried into solution by the sulphuric acid. The presence of lead will serve to identify sludge 
asphalts, and differentiate them from all other asphaltic substances. The author's investigations 
revealed lead varying in amounts from 0.05 to 0.25 per cent. 



306 



ASPHALTS AND ALLIED SUBSTANCES 



fatty-acid pitch, comparing respective products of the same fusing-point 
and volatility, or of the same hardness and volatility. They are substan- 
tially equal in weather-resistance to the corresponding grades of pitch 
derived from coal and bones, and are superior to those derived from 
rosin, wood, peat and lignite. In practice, they are usually fluxed with 
other forms of petroleum asphalt, rather than marketed in their pure 
state. 

TABLE XXVII.— CHARACTERISTICS OF TYPICAL SLUDGE ASPHALTS 



No. 



9d 
106 



11 



Test. 



Physical Characteristics 
Homogeneity to eye at 77° F. . . . 
Homogeneity under microscope. . . 
Appearance surface aged 7 days. . 

Fracture 

Lustre 

Streak 

Specific gravity at 77° F 

Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

Susceptibility factor 

Ductility in cms. at 115° F 

Ductility in cms. at 77° F 

Ductility in cms. at 32° F 

Tensile strength in kg. at 115° F. 
Tensile strength in kg. at 77° F. . 
Tensile strength in kg. at 32° F. . 



From Various Sources, Mostly Mixtures. 



Homo. 
Homo. 
Bright 



Black 
1.057 
0.0 
3.4 

42.2 
49.7 

7 
38 

1.5 

0.0 

0.4 
10.5 



Homo. 
Homo. 
Bright 



Black 

1.052 

0.0 

7.1 
58.8 
59.5 
15 
82 


0.1 

1.4 

4.5 



Homo. 
Homo. 
Bright 
Conch. 
Bright 
Black 

1.068 

0.0 
17.5 
71.8 
61.8 
45 
18 


0.35 

3.85 

3.0 



Homo. 
Homo. 
Bright 
Conch. 
Bright 
Black 

1.090 

0.0 
19.9 
85.4 
53.4 

3.5 

0.75 


1.3 

5.4 

8.0 



Homo. 
Homo. 
Bright 
Conch. 
Bright 
Black 

1.076 
43.1 
87.9 
>100 
> 50 



3.0 
7.5 
6.0 



Homo. 
Homo. 
Bright 
Conch. 
Bright 
Black 

1.155 

50.7 

95.2 

>100 

> 50 







3.5 

8.2 

5.5 



15a 

156 

16 

17a 

19 



21o 

216 

21c 

22 

23 



Heat Tests 
Fusing-point, deg. F. by K. & S. method. 
Fusing-point, deg. F. by B. & R. method. 
Volatile, 500° F. in 4 hrs., per cent. . . . 

Flash-point, deg. F 

Fixed carbon, per cent 



85 
101 

3.0 
475 

8.8 



113 

2.2 
500 
12.3 



116 
134 

7.9 
430 
16.1 



160 
178 

2.5 
480 
22.0 



203 
225 

4.8 
482 
30.2 



210 
230 

5.0 
486 
25.4 



Solubility Tests 
Soluble in carbon disulphide. . 
Non-mineral matter insoluble. 

Mineral matter 

Carbenes 

Soluble in 88° naphtha 



98.98 
0.90 
0.12 
0.0 

93.2 



99.72 
0.20 
0.08 
0.2 

94.0 



99.51 
0.38 
0.11 
2.3 

78.7 



99.23 
0.72 
0.05 
1.0 

74.6 



99.50 
0.40 
0.10 
1.2 



97.50 
2.43 
0.07 
13.2 
62.2 



Chemical Tests 

Sulphur 

Paraffine 

Saturated hydrocarbons 

Sulphonation residue 



8.7 
0.5 
9.0 

82.1 



7.8 
0.4 



88.0 



5.4 
0.2 

7.2 



7.5 

0.25 

5.5 



6.2 
0.1 

4.8 



8.3 

0.1 

3.9 

93.2 



CHAPTER XX 
PARAFFINE WAX AND WAX TAILINGS 

PARAFFINE WAX 

The commercial sources of pyrogenous paraffine wax are: 

(1) Peat tar; 

(2) Lignite tar; 

(3) Shale tar; 

(4) Paraffine-bearing petroleums. 

The peat distilling industry is comparatively unimportant and does 
not form a factor in the production of paraffine. The lignite industry 
has only attained commercial importance in Germany, and the shale 
industry in Scotland. The treatment of paraffine-bearing petroleums 
for the recovery of parafl&ne is important the world around. The methods 
for recovering paraffine wax from lignite tar, shale tar and petroleum are 
substantially the same. In the case of lignite tar, the paraffine wax is 
obtained from the distillate fractioned after the crude oil, known as the 
'' paraffinaceous mass" (p. 211). With shale tar the paraffine wax is 
obtained from the distillate known as '' heavy oil," distilling after the 
"intermediate or gas-oil" (p. 223). With paraffine-bearing petroleums, 
the paraffine wax is obtained from the fraction known as the " paraffine 
distillate." 

In all three cases the following steps are generally pursued: 

The distillate containing the paraffine is first chilled to 20 to 25° F. 
by forcing it through a series of jacketed 6 in. pipes. Brine cooled to 15 
to 20° F. is circulated through the jacket, and the distillate containing the 
paraffine is forced through the inner pipe by a slowly revolving spiral con- 
veyor, which continually keeps the distillate moving as it solidifies, thus 
tending to granulate it and thus make it easier to filter. 

The cooled and solidified distillate having the consistency of heavy 
mush is transferred to high-pressure filter presses provided with canvas- 
covered plates, and while still cool filtered at a pressure of 300 to 350 lb., 
causing the pressed oil to separate from the " slack wax." 

The slack wax still contains between 30 and 50 per cent of oily matters 
which are separated by a process known as '' sweating." A " sweater " 

307 



308 



ASPHALTS AND ALLIED SUBSTANCES 




Fig. 115. — Paraffine Wax Sweater. 



(Fig. 115) carries 8 to 10 superimposed shallow pans (18 by 20 by 1 ft.), 

each provided with a wire gauze 
diaphragm A stretched across longitu- 
dinally 6 in. below the top, also: 

(1) An inlet for introducing the 
melted slack wax. 

(2) An inlet pipe for water. 

(3) An outlet pipe C connected 
with the bottom of each pan at its 
centre. 

(4) A water-circulating coil B 
directly above the diaphragm through 
which cold water is first circulated to 
chill the wax, followed by warm water 
to induce the " sweating." 

(5) A steam coil directly below the 
diaphragm to melt down the wax after the sweating process is completed. 

The operations are performed in the following rotation: 

(1) The pans are first filled with cold water to J in. above the level 
of the screens. 

(2) The melted " slack wax " is pumped into the pans to a depth of 
4 in. and allowed to float on the water. 

(3) Cold water is then caused to flow through the water-circulating 
system, which causes the slack wax to set into a solid mass. 

(4) The water is then drawn off, whereupon the cake of solid wax 
settles upon the wire diaphragm. 

(5) Warm water is then caused to flow through the water-circulating 
coils at a temperature just below the melting-point of the wax, which 
causes the oily matters to Hquefy and "sweat out " from the crystals of 
paraffine, with the result that the purified paraffine now known as " crude 
wax " remains on the wire gauze. The oily matter carrying a small pro- 
portion of wax in solution, known as " foots oil " is drawn from the pans. 
The purified paraffine wax is melted by turning steam into the melting- 
down coils and drawn from the pans into a separate container. It takes 
about twenty-four hours to properly sweat a batch of slack wax. 

The foots oil is put through the chilling process a second time to 
recover any dissolved wax, which when separated is known as '' crude 
scale wax " (see chart page 278). 

The crude wax and the crude scale wax are decolorized by filtering 
through fuller's earth in vertical cylindrical tanks heated to 180° F. The 
melted wax is allowed to run through the filters by gravity from an over- 



PARAFFINE WAX AND '\VAX TAILINGS 309 

head storage tank where it is maintained in a melted condition. The 
filters are from 15 to 20 tons' capacity, the fuller's earth being supported 
on a finely perforated false bottom. One ton of the earth will decolorize 
5 to 6 tons of the wax. 

When the fuller's earth loses its efficiency, which is evidenced by the 
filtrate no longer remaining clear in color, the flow of wax is shut off, the 
filter bed thoroughly drained and washed with naphtha to remove any 
wax retained mechanically. Any naphtha remaining in the filtering 
medium is recovered by introducing steam and passing the vapors through 
a condenser. The wax removed by the naphtha is recovered by distilla- 
tion, and added to the unfiltered material. 

The fuller's earth may be rejuvenated by heating in a suitable kiln, 
after which it can be used over again without loss in efficiency. 

The filtered products obtained from the crude wax and crude scale 
wax are known as " refined paraffine wax " and *' refined scale wax '' 
respectively. These are pumped into moulds and allowed to solidify. 
The wax must be chilled very quickly to form the opaque white mass 
demanded by the trade, otherwise it will appear translucent, which is 
undesirable.^ 

Paraffine wax, including both the " refined paraffine wax " and the 
^' refined scale wax " tests as follows: 

(Test 1) Color in mass Pure white to yellowish 

(Test 2a) Homogeneity to the eye at room temperature . . . Uniform to slightly crys- 
talline 

(Test 2c) Homegeneity when melted Uniform and transparent 

(Test 4) Fracture Conchoidal to hackly 

(Test 5) Lustre Dull and " waxy " 

(Test 6) streak White 

(Test 7) Specific gravity at 77° F 0.85- 0.95 

(Test 9c) Consistency at 77° F 15 -80 

(Test 9d) Susceptibility factor > 100 

(Test 10) Ductility at 77° F 

(Test 14a) Behavior on melting Passes almost instanta- 
neously from the solid 
to the liquid state 

(Test 15a) Fusing-point 2 (K. & S. method) 100-150° F. 

(Test 156) Fusing-point (B. & R. method) 105-160° F. 

(Test 16) Volatile matter Comparatively great 

*" Mineral Waxes," Rudolf Gregorious, London, 1908; "Shale Oils and Tars," by Dr. W. 
Scheithauer, London, 1913; "Industrial Chemistry," by Allan Rogers, 2d edition, p. 512, New 
York, 1915; "The American Petroleum Industry," by Bacon and Hamor, Vol. 2, pp. 459 and 
753, New York, 1916. 

2 The fusing-point of paraffine wax is generally determined by the so-called "English method," 
which consists in cooling the melted wax, with a thermometer immersed in the mass. The drop 
in temperature and time intervals are carefully noted. When the temperature remains constant 
for an appreciable interval, the wax is said to have reached its fusing or "melting-point." Accord- 
ing to the "American method," the melting-point is reached when crystals of paraffine first 
appear on the surface of the cooling wax, but is often arbitrarily calculated by adding 3° F. to 
the melting-point ascertained by the English method. 



310 ASPHALTS AND ALLIED SUBSTANCES 

(Test 17a) Flash-point Comparatively low 

(Test 18) Burning-point Comparatively low 

(Test 19) Fixed carbon 0- 2% 

(Test 21a) Solubility in carbon disulphide 99-100% 

(Test 216) Non-mineral matter insoluble Trace 

(Test 21c) Mineral matter Trace 

(Test 22) Carbenes 0% 

(Test 23) Solubility in 88° naphtha 99-100% 

(Test 24) Solubility in other solvents (weight solvent re- 
quired to dissolve 1 gram of paraffine at 
room temperature) : 

Carbon disulphide 7.6 

Petroleum ether 8.5 

Turpentine 16.1 

Chloroform 41.3 

Benzol 50.3 

Ether 50.8 

Acetone 378 . 7 

Absolute ethyl alcohol 453. 6 

Amyl alcohol 495 . 3 

Methyl alcohol 1447 . 5 

Glacial acetic acid 1668 . 6 

(Test 26) Carbon 84- 86% 

(Test 27) Hydrogen 13- 15% 

(Test 28) Sulphur Trace 

(Test 29) Nitrogen Absent 

(Test 30) Oxygen Trace 

(Test 33) Paraffine 95-100% 

(Test 34) Saturated hydrocarbons 90- 99% 

(Test 35> Sulphonation residue 95-100% 

(Teat 37) Saponifiable constituents 0% 

(Test 41) Diazo reaction No 

(Test 42) Anthraquinone reaction No 

Paraffine wax is remarkably resistant to the action of chemicals, but 
on exposure to the weather the oily constituents soon evaporate, leaving 
a pulverulent and but slightly coherent mass behind. This is not due to 
oxidation, but merely to volatilization of the oils present in the wax. 

Paraffine wax withstands the continuous action of water very well and 
finds a ready market for preparing waterproof papers, for manufacturing 
candles, for household purposes, etc. 



WAX TAILINGS 

This product is obtained during the dry distillation of non-asphaltic 
or mixed-base petroleum. The residuum left in the retort at the end 
of the first distillation is subjected to a second process of dry distil- 
lation, whereupon the wax tailings distils over just prior to the forma- 
tion of coke. (See p. 282.) Wax tailings is sometimes termed *' still 
wax," although both these names are misnomers, since it contains 
only small quantities of paraffine wax. It consists largely of decomposi- 
tion products, including chrysene, picene and anthracene, and has a decided 



PARAFFINE WAX AND WAX TAILINGS 311 

yellow color, by which it is recognized during the process of distillation. 
Upon cooling it forms a very viscous semi-liquid to sticky semi-solid of a 
characteristic light yellow to yellowish brown color. It complies with the 
following tests: 

(Test 1) Color in mass Yellow to yellowish brown 

(Tlest 2a) Homogeneity to the eye at room temperature. . . Uniform to very slightly 

granular 

(Test 26) Homogeneity under microscope Uniform to gritty (due to 

the crystalline constit- 
uents present) 

(Test 3) Appearance surface aged indoors Variable 

(Test 5) Lustre Waxy 

(Test 6) Streak on porcelain Pale yellow 

(Test 7) Specific gravity at 77° F 1 .00- 1 . 10 

(Test 9c) Consistency at 77° F 5 -20 

(Test 9d) Susceptibility factor 20-40 

(Test 10) Ductility at 77° F Usually quite high 

(Test 13) Odor on heating Oily 

(Test 14a) Behavior on melting Passes very rapidly from 

the solid to the liquid 
state 

(Test 15a) Fusing-point (K. & S. method) 60-100° F. 

(Test 16o) Volatile matter at 500° F., 4 hrs 5-10 % 

(Test 17a) Flash-point 300-450° F. 

(Test 19) Fixed carbon 2- 8% 

(Test 21o) Solubility in carbon disulphide 98-100% 

(Test 216) Non-mineral matter insoluble 0- 2% 

(Test 21c) Mineral matter O-Trace 

(Test 22) Carbenes O-Trace 

(Test 23) Solubility in 88*' naphtha 95-100% 

(Test 28) Sulphur O-Trace 

(Test 30) Oxygen 0- 2% 

(Test 32) Naphthalene Absent 

(Test 33) Paraffine Tr.- 5% 

(Test 34) Saturated hydrocarbons 40- 70% 

(Test 35) Sulphonation residue 90-100% 

(Test 37) Saponifiable constituents Trace 

(Test 41) Diazo reaction No 

(Test 42) Anthraquinone reaction Yos 

Wax tailings is an exceedingly good flux, and will thoroughly amalgamate with 
the harder asphalts and asphaltites, including even grahamite. It forms a better 
flux than the residual oils derived from asphaltic petroleum. A very small per- 
centage will often serve to thoroughly flux materials which are otherwise incom- 
patible, and at the same time increase the ductility of the mixture. Certain as- 
phalts, although they may flux together at high temperatures, will separate partially 
on cooling, forming a very finely granular condition, which is particularly noticeable 
when the surface of the mixture is freshly disturbed, or upon drawing a small 
pelhcle into a thread. The presence of a small percentage of wax tailings will 
often prevent this, and it therefore enjoys a unique position among the fluxes. 
Large quantities, however, should be avoided as wax tailings is extremely susceptible 
to changes in temperature and lacks weather-proof properties. The presence of 
wax tailings will increase the solubility of asphaltic substances in petroleum dis- 
tillates, and accordingly becomes useful for manufacturing certain types of bitu- 



312 ASPHALTS AND ALLIED SUBSTANCES 

minous paint. A representative sample of wax tailings tested by the author gave 
the following results: 

(Test 9c) Consistency at 115° F 0.0 

Consistency at 77° F 5.9 

Consistency at 32° F 22 . 9 

(Test 9d) Susceptibility factor 25 . 

(Test 106) Ductility at 115° F 1.1 

Ductility at 77° F 3.9 

Ductility at 32° F 13.5 

(Test 11) Tensile strength at 115° F 0.0 

Tensile strength at 77° F 0.5 

Tensile strength at 32° F 9.5 

(Test 15o) Fusing-point (K. & S. method) 90° F 

(Test 156) Fusing-point (B. & R. method) 98° F. 

(Test 17a) Flash-point 382° F. 

The production of wax tailings is not large, and it is not, therefore, of great impor- 
tance to the asphalt industry. 



CHAPTER XXI 

WURTZILITE ASPHALT 

WuRTZiLiTE asphalt or wurtzilite pitch, marketed under the name of 
" kapak," is produced by cracking or depolymerizing wurtzilite (p. 150). 
It is similar to the latter in its physical characteristics with the excep- 
tion of: 

(1) The hardness, which is very much reduced. 

(2) Its fusibility. Treated wurtzilite is fusible whereas crude wurtzi- 
lite is not. 

(3) Its solubility. Treated wurtzilite is readily soluble in carbon 
disulphide, and moderately so in 88° naphtha, whereas the crude product 
is practically insoluble in both. 

The process consists in heating the wurtzilite in a closed vessel 
or still to a temperature of 500 to 580° F., under more or less pressure. 
Vapors are evolved during the process which are condensed and returned 
to the still, and in turn attack the wurtzilite, first reducing it to a plastic 
mass, which after heating is converted into a fusible substance. If the 
vapor pressure becomes too great, some is allowed to escape. The proc- 
ess which takes place is virtually a '^ depolymerization " (see p. 58). ^ 

In practice, the wurtzihte is first run through a crusher to break up 
any coarse lumps, and then fed into a horizontal cylindrical still through 
two charging hoppers, one at either end, provided with tightly fitting 
covers which are fastened into place before the fires are started. The 
bottom of the still is protected by a fire-brick arch, and the products of 
combustion after passing underneath the arch, are returned in three 
fire-flues running through the still (one 10 in. in diameter and two 6 in.), 
and thence back aga.n in the space surrounding the still, above the arch. 
The vapors generated from the wurtzilite pass upward through two pipes 
joined to the top of the still, near the ends, and connected with a single 
water-cooled coil, which condenses the vapors and returns niost of the 
condensate to the still. Not all the condensate is returned, however, for 

lU. S. Pats. 616,047 of Dec. 13, 1898, 617,706 of Jan. 17, 1899, and 620,082 of Feb. 21, 
1899, all to C. E. Anthony; 655,130 and 655,131 of July 31, 1900 also 716,787 of Dec. 23, 1902, 
all to R. M. Thompson; 734.482 and 734.483 of July 21, 1903 to S. R. Whitall; 768,101 of 
Aug. 23, 1904 to F. M. Whitall; 864,836 of Sept. 3, 1907 to W. F. Doerflinger and L. H. Buck; 
984,240 of Feb. 14, 1911 to J. C. Ross. 

313 



314 ASPHALTS AND ALLIED SUBSTANCES 

practice has demonstrated that the optimum results are obtained if 
2 to 5 per cent of the distillate (based on the weight of wurtzilite charged 
into the still) is drawn off. This may be used as fuel under the still. 

The longer the wurtzilite is heated in its process of manufacture 
the greater the quantity of oils produced, which act in the same manner 
as a flux, and hence lower will be the fusing-point and hardness of the 
resultant product. 

It takes six to eight hours to raise the temperature of the charge to 
400° F., then four to six hours to reach the maximum temperature (580° 
F.), which is maintained from twenty-four to thirty-six hours. The 
contents are then allowed to cool to 450° F., and finally drawn off through 
a valve at the bottom. 

According to the author's investigations, Nova Scotia albertite is 
also amenable to this process, although up to the present time it has not 
been treated thus commercially. 

The wurtzilite products are marketed under various arbitrary numbers 
ranging from *' " to " 16," each of which is recommended for a specific 
purpose, including the manufacture of paints and varnish, insulators, for 
manufacturing insulated wire, for weather-proofing conduits and cables, 
as a filler for mechanical and hard rubber compounds cured by the press 
or open steam method, for coating prepared roofings, for manufacturing 
carriage drills and similar compositions applied by the calendar process 
and cured by the dry heat method, etc. Certain of these compounds 
represent mixtures of wurtzilite asphalt and gilsonite, with or without 
the addition of asphaltic fluxes (e.g. residual oil), and vegetable oils 
(e.g., linseed oil, palm oil, etc.)o 

Wurtzilite asphalt complies in general with the following characteristics: 

(Test 11) Color in masa . Black 

(Test 2a) Homogeneity to the eye at room temperature Uniform 

(Test 26) Homogeneity under microscope Uniform 

(Test 3) Appearance surface aged indoors one week Very bright 

(Test 4) Fractiire Conchoidal 

(Test 5) Lustre Bright 

(Test 6) Streak on porcelain Brown to black 

(Test 7) Specific gravity at 77° F 1.04- 1.07 

(Test 9c) Consistency at 115° F 10 - 25 

Consistency at 77° F 20 - 50 

Consistency at 32° F 50 -120 

(Test 9d) Susceptibility factor 30 - 40 

(Test 106) Ductility at 115° F 1-5 

Ductility at 77° F 0-1 

Ductility at 32° F 

(Test 11) Tensile strength at 115° F 1 - 4 

Tensile strength at 77° F 5 - 10 

Tensile strength at 32° F 8 - 15 

(Test 15a) Fusing-poiat (K. & S. method) 150 -300° F. 



WURT2ILITE ASPHALT 



315 



(Test 156) Fuslng-point (B. and R. method) 170 -325° F. 

(Test 16a) Volatile matter, 500° F., 4 hours Less than 5% 

(Test 17a) Flash-point 450 -600° F. 

(Test 19) Fixed carbon 5 - 25% 

(Test 21a) Solubility in carbon disulphide 98 -100% 

(Test 216) Non-mineral matter insoluble - ^% 

(Test 21c) Mineral matter Tr. - 2% 

(Test 22) Carbenes - 2% 

(Test 23) Solubility in 88° naphtha 50 - 80% 

(Test 28) Sulphur 4 - 6% 

(Test 30) Oxygen 0- 2% 

(Test 33) Paraffine -Trace 

(Test 34) Saturated hydrocarbons 5 - 12% 

(Test 35) Sulphonation residue 90 - 95% 

(Test 37) Saponifiable constituents Trace 

(Test 41) Diazo reaction No 

(Test 42) Anthraquinone reaction No 

Specimens of the unfluxed wurtzilite asphalt examined by the author tested as 
follows : 



(Test 9c) Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

(Test 9d) Susceptibility factor 

(Test 15a) Fusing-point (K. and S. method) 
(Test 106) Ductility at 115° F 

Ductility at 77° F 

Ductility at 32° F 



No. 0. 


No. 1. 


No. 6. 


22.9 


18.5 


15.0 


45.6 


41.8 


38.5 


110.0 


92.2 


80.6 


32.4 


33.4 


32.8 


269 


220 


200 


2 


3 


3 





















No. 1( 



11.7 
32.4 
71.1 
31.2 
190 
4 

i 




These figures indicate that the extent of softening and lowering of the fusing- 
point is dependent upon the extent to which the process of depolymerization has 
progressed. It is interesting to observe in this connection that the susceptibiltiy 
factor remains practically unchanged. 



Wurtzilite asphalt is characterized by its low specific gravity, high- 
fusing-point, low susceptibility factor, extreme toughness and rubber- 
like properties (i.e., resiliency), high-tensile strength, small percentages 
of oxygen and non-mineral matter, large percentage of sulphonation 
residue, and absence of saponifiable constituents. 

It is quite similar in many respects to blown asphalts (particularly in 
regard to its susceptibility factor), but may be differentiated from 
these by: 

(1) A greater hardness or consistency at 77° F. for any given fusing- 
point. 

(2) A greater tensile strength for any given fusing-point. 

(3) Smaller percentages of oxygen. 

(4) Smaller percentages of saturated hydrocarbons. 



316 ASPHALTS AND ALLIED SUBSTANCES 

Wurtzilite asphalt is also similar in many respects to the fatty-acid 
pitches, especially in its toughness (resilience) and its low susceptibility 
factor. It is distinguished from these, however, by the following: 

(1) Its solubility in 88° naphtha, which is smaller than in the case 
of fatty-acid pitches. 

(2) The presence of sulphur, which is absent in the fatty-acid pitches. 

(3) The smaller percentage of oxygen. 

(4) The larger percentage of sulphonation residue. 

(5) The absence of saponifiable constituents. 

In other respects they are apt to test pretty nmch alike. 

Wurtzilite asphalt shows remarkable weather-resistance and finds its 
greatest use in manufacturing asphalt paints and for coating prepared 
roofings. Its use is limited by the small quantity produced, and the com- 
paratively high price at which it is marketed. 



CHAPTER XXII 

FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 

These are classified together because all are derived from substances 
containing animal or vegetable fats or oils, although in manufacturing 
bone tar and bone-tar pitch the crude materials carry but a small propor- 
tion. 

FATTY-ACID PITCH 

Various generic terms have been used to designate this product, 
including candle tar, '' Kerzenterr " (German), " goudron " (French), 
candle pitch, fat pitch and " Fettpech " (German). Specific names 
have also been applied, descriptive of the raw materials used in pro- 
ducing the pitch, such as stearin pitch, palm-oil, pitch, bone-fat pitch, 
cotton-seed-oil pitch, cotton pitch, cotton-stearin pitch, cotton-seed - 
foots pitch, corn-oil pitch, corn-oil-foots pitch, packing-house pitch, 
garbage pitch, sewage pitch, fuller's-grease pitch, wool pitch, wool- 
grease pitch, wool-fat pitch, cholesterol pitch, and stearin-wool pitch. 

The iatty-acid pitches are obtained as by-products in the following 
manufacturing processes : 

(1) Production of candle and soap stocks. 

(2) Refining vegetable oils by means of alkalies. 

(3) Refining refuse greases. 

(4) Treatment of wool grease. 

The raw materials used include the vegetable oils and fats, animal 
oils, fats and waxes (wool grease), also the waste greases derived from the 
foregoing. Vegetable and animal fats and oils are combinations of the 
fatty acids with glycerin, known as " triglycerides," and illustrated by the 
following generic formula, in which ^' R " represents any fatty acid radicle: 

.OR 

CsHs^OR 

^OR 

Fats and oils may be purified or refined in two ways: 
(1) By treating vegetable oils with a small amount of caustic soda 
to remove the coloring matter, free fatty acids and other impurities, with- 

317 



318 ASPHALTS AND ALLIED SUBSTANCES 

out, however, breaking up the triglycerides. This process is used for refin- 
ing vegetable oils when they are to be used for edible purposes. The resi- 
due is treated with mineral acid to break up the soaps, and then distilled 
with steam to recover the fatty acids, whereupon a residue of fatty-acid 
pitch is obtained. 

(2) By decomposing or '^ hydrolyzing " the triglycerides into glycerin 
and free fatty acids, and then distilling the latter with steam, whereby 
fatty-acid pitch is obtained as a residue. The object of distilling the fatty 
acids is to improve their color or odor and thereby adapt same (a) for the 
manufacture of candles (which are commonly light colored or white), 
or (b) for manufacturing soaps (such as toilet soaps, etc.) which must 
be odorless and preferably light-colored. 

Production of Candle and Soap Stocks. These are obtained from 
various animal and vegetable oils and fats, also from waste greases. It 
is always necessary to subject the fatty acids to a process of hydrolysis 
and steam distillation for producing candles, but not for manufacturirg 
soaps, unless the fatty acids are too dark in color for the character of soap 
required or possess a disagreeable odor, in which event they are purified 
by distillation. Various methods of hydrolysis may be used, but they 
all depend upon the same reaction, in which the triglyceride combines 
with water and decomposes into glycerin and fatty acids, as illustrated 
in the following equation: 

C3H5^0R+3HOH = C3H5^0H+3 ROH. 
^OR ^OH 

Triglyceride Water Glycerin Free Fatty Acid 

(fat or oil) 

It is necessary to hydrolyze the fats or oils before distilling the fatty 
acids, since the triglycerides themselves are not capable of being distilled 
without decomposition. The following methods of hydrolysis have been 
used: 

(a) Hydrolysis hy Means of Water. Formerly, water alone was used 
for the purpose, the fat or oil being heated in an autoclave with 30 per 
cent of its weight of water at 220 lb. pressure (corresponding to a tempera- 
ture of 200° C.) for eight to twelve hours. This decomposes the triglyceride 
into fatty acids and glycerin, but with water alone it is diflficult to break 
down the fat completely. It has been found that the addition of 3 per 
cent of lime or magnesium oxide, and preferably the latter, assists the 
reaction and produces a larger yield of a better product, and at a much 
lower temperature. Accordingly the fat or oil is heated at 120 lb. pres- 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 319 

sure in a horizontal or vertical cylindrical vessel provided with a stirring 
device, with 20 to 25 per cent by weight of water and 3 per cent of 
lime or magnesium oxide. The breaking down of the fat is practically 
complete at the end of eight to ten hours, and in addition the color is very 
much better, as there is less decomposition, due to the lower temperature 
employed. The fats or oils used for this purpose may consist of animal 
or vegetable tallow, palm oil, bone fat, lard- or cotton-seed stearin (crystal- 
lized at low temperatures from lard or cotton-seed oil respectively), shea 
butter, etc. 

At the end of the process, the free fatty acids rise to the surface and are 
skimmed off, leaving the aqueous liquor containing the glycerin (together 
with the hydrated lime or magnesia, when the latter are used). The 
glycerin is recovered by a special process which, however, does not fall 
within the scope of this treatise. The fatty acids are subjected to steam 
distillation to deodorize and whiten them, also to purify them by separating 
any non-hydrolyzed fat. The fatty acids are run into lead-lined tanks 
where they are first treated with dilute sulphuric acid to remove any traces 
of magnesium oxide, etc., then washed with water, heated to expel the 
moisture, after which they are fed into a retort and distilled with super- 
heated steam with or without the use of vacuum. The fatty acids suitable 
for distillation should not contain more than 5 per cent of non-hydrolyzed 
fat (neutral fat) nor more than 0.2 per cent of mineral matter. To obtain 
a distillate of good quahty, care should be taken not to distil the fatty 
acids at too high a temperature as they are extremely susceptible to over- 
heating and decomposition into dark-colored hydrocarbons (unsapon- 
ifiable), which would, of course, depreciate the value of the distillate. 
The still should be constructed so that the flames will not come into 
direct contact with the bottom and cause local overheating. The 
temperature of the material in the still should preferably be maintained 
between 230 and 250° C, and although in certain instances it is permissible 
to reach a temperature of 270° C, under no circumstances should this be 
exceeded. 

Two methods are used for conducting the distillation. The first 
consists in continuously replacing the fatty acids, as they distil with an 
equivalent quantity of undistilled material, as long as the distillate shows 
a satisfactory color and is free from unsaponifiable hydrocarbons. The 
effect of the distillation is to concentrate the impurities and unsaponified 
(neutral) fats or oils in the still. The distillation conducted in this manner 
may be continued for five to six days before it becomes necessary to clean 
out the retort, which is then filled entirely with a soft fatty-acid pitch. 
The second method consists in replacing the distilled fatty acids for but 



320 



ASPHALTS AND ALLIED SUBSTANCES 



sixteen to twenty-four hours, then discontinuing the addition, and dis- 
tilhng the contents of the retort until the distillate ceases to be of suitable 
quality, as is evidenced by a change in its color. The residue consisting 
of soft fatty-acid pitch is then drawn off into a separate still known as the 
" pitch still," the first still recharged, and the process repeated, until after 
a sufficient number of distillations a sufficient quantity of soft fatty- 
acid pitch accumulates for further treatment. It is claimed that the second 
method gives better results and yields a distillate lighter in color and con- 
taining a smaller percentage of hydrocarbons. 

In either case the soft residue is distilled separately with superheated 
steam and vacuum. When the neutral fats increase in concentration to 
12 to 15 per cent they commence to decompose into hydrocarbons, some of 
which distil with the fatty acids and some remaining with the residue. 
This portion of the distillate known as " still returns " is accordingly 
caught separately and returned to the first still to be worked up with 
another charge of undistilled fatty acids, whence it derives its name. The 
final residue constitutes the so-called " fatty-acid pitch." 

The following figures will give an idea of the yields from the fatty 
acids derived from fats and oils hydrolyzed by the treating with 2.6 to 
3 per cent of magnesium oxide at a pressure of nine atmospheres for 
eight to ten hours. ^ 



Lard stearin . . . . 
Vegetable tallow 

Tallow 

Bone fat 

Palm oil 

Shea butter 



Quantity 


Time Dis- 


Yield 


Still 


Distilled, 


tillation, 


Distillate, 


Returns, 


Tons. 


Hours. 


Per Cent. 


Per Cent. 


8 


36 


95.6 


2.1 


5 


35 


92.4 


4.0 


5 


36 


94.2 


2.3 


5 


38 


91.5 


5.0 


5 


37 


91.3 


4.5 


5.3 


29 


94'. 1 


2.4 



Fatty-acid 
Pitch, 
Per Cent. 

2.3 
3.6 
3.5 
3.5 

4.2 
3.7 



The distilled fatty acids are next separated into two portions represent- 
ing those of low and high molecular weights respectively, by cooling and 
crystallization. The mass is first cooled to a low temperature and filter- 
pressed. The filtrate known as the " saponification olein " is cooled 
again and repressed to separate any additional quantities of " saponifica- 
tion stearin." The latter is combined with the " saponification stearin " 
separated from the first pressing which is then treated at a higher tem- 
perature in a steam-heated press to remove the last traces of ** saponifica- 
tion olein." The following yields are obtained: 



1 Kassler, Chem. Rev. Fett-Harz-Ind., 9, 49, 1902. 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 321 





Producing Low 

Melting-point 

Stearin, 

Per Cent. 


Producing High 

Melting-point 

Stearin, 

Per Cent. 


Saponification stearin 

Saponification olein 

Saponification glycerin (sp. gr. 1.24).. 


49-51 

42-41 

9-10 

4-5 


44-46 

47-40 

9-10 

4-5 





The saponification stearin may be used for manufacturing candles, 
in which event it is generally mixed with a certain percentage of paraffine 
wax, or in some instances it may be used for producing hard white soaps. 
The saponification olein may be used for manufacturing soaps or wool 
oils (cloth oils), or it may be converted by a hydrogenation process into 
substances of higher melting-points, suitable for producing candles. 

(b) Hydrolysis by Means of Concentrated Sulphuric Acid} The fats or 
oils are first freed from moisture by heating to a temperature of 120° C. 
It is essential that all the moisture be removed to prevent excessive 
decomposition. The mass is then rapidly mixed with 4 to 6 per cent 
of concentrated sulphuric acid (66 to 67° Baume) and heated in a cylin- 
drical vessel provided with a mechanical agitator. The heating is con- 
tinued just long enough to break up the triglycerides and no longer. 
The sulphonated mass is then immediately run into boiling water and 
agitated by a steam jet until the sulphonated acids hydrolyze. The 
mass is then allov^ed to stand quietly until the free fatty acids rise to 
the surface, leaving the glycerol and sulphuric acid in the lower layer. 

The fatty acids produced in this manner are dark colored and must 
be distilled. They are first washed with water until neutral, then heated 
to expel the moisture and finally distilled with superheated steam with or 
without a vacuum as previously described, whereupon a residue of soft 
fatty-acid pitch is obtained. According to modern practice, this residue is 
again treated with concentrated sulphuric acid to hydrolyze any neutral 
fats remaining, and incidentally remove the accumulated mineral matter 
(including an}^ copper or iron derived from the stills). It is then washed 
free from the acid and redistilled, leaving a residue of medium to hard 
fatty-acid pitch. The dark colored distillate, known as " still returns," 
is worked up in small quantities with the crude fatty, acids undergoing 
their first distillation. 

The yield of stearin known in this case as *' distillation stearin " is 
greater than that obtained in the aqueous process of hj^drolj^sis, due to the 
fact that some of the olein (in this case known as '^ distillation olein " 

»0. Rosauer, Chem. Rev. Fett-Harz-Ind., 15, 174, 1908. 



322 



ASPHALTS AND ALLIED SUBSTANCES 



or " distilled olein ") is converted into a solid product (consisting of 
stearolactone, isomeric oleic acid, etc.). The olein and stearin are separated 
by cooling exactly as in the foregoing process. A smaller yield of glycerin 
is obtained due to its partial decomposition by the acid, and that of fatty- 
acid pitch is also less and of a darker color. 
The following jdelds are obtained: 

Distilled stearin or distillation stearin 61-63% 

Distilled olein or distillation olein -. ;-. 30-32% 

Distilled glycerin or distillation glycerin 8 -9% 

Fatty-acid pitch 2- 3% 

To avoid losing the glycerin, which constitutes one of the most impor- 
tant and highest priced products, a " mixed process " is now used consist- 
ing of a combination of the foregoing. 

(c) Hydrolysis by the ^' Mixed Process, '^ This is a combination of the 
two foregoing processes, and consists in first hydrolyzing the fats or oils 
in an autoclave with water and an alkaline accelerating agent (such as 
lime or magnesium oxide), and in this way recovering the full amount of 
glycerin. The resulting fatty acids are dehydrated and treated with 
concentrated sulphuric acid in accordance with process (6) to increase the 
yield of stearin and complete the hydrolysis of any neutral fat which may 
have escaped the first treatment, and thus minimize the formation of hydro- 
carbons in the distillate. 

The following yields are obtained: 





Quantity 

Distilled, 

Tons. 


Time Dis- 
tillation, 
Hours. 


Yield, 
Distillate, 
Per Cent. 


Still 
Returns, 
Per Cent. 


Fatty-acid 

Pitch, 
Per Cent. 


Tallow 


5-7 

5-5.6 

5 


33-34 
34-35 
32-36 


94.6-94.8 
90.3-92.8 
91.0-91.6 


2.0-2.6 
4.2-5.4 
4.6-5.3 


2.8-3.2 




3.0-4.3 


Palm oil 


3.7-3.8 







The following products are obtained on treating tallow: 

Distilled stearin 61-63% 

Distilled olein 32-30% 

Distilled glycerin (sp. gr. 1.24) 10% 

Fatty-acid pitch 2- 3% 

(d) Hydrolysis hy Means of Sulpho-compounds. This process, known 
as the Twitchell method, is rapidly replacing the others, and is now 
employed in soap factories for treating the fats or oils before soap-making, 
as it separates a purer glycerin and at the same time results in a greater 
yield (88 to 90 per cent of the theoretical quantity contained in the fat 
or oil vs. 80 to 84 per cent obtained in the direct caustic soda saponificatior 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 323 

method for soaps). Moreover, the hquor separated in the Twitchell 
process is not contaminated with the sodium chloride used for '' salting 
out " the soap in the ordinary method, and it contains 15 per cent by 
weight of glycerin against 3 to 4 per cent in the liquor obtained on direct 
saponification of the fats or oils with sodium hydroxide. The former 
therefore effects a saving in evaporation. 

The fat or oil is first purified by steaming with 1 per cent of 60° Baume 
sulphuric acid for about two hours. It is then transferred to a wooden 
vessel equipped with perforated steam pipes also a well-fitting cover to 
exclude air which would cause the fatty acids to darken, and mixed with 
50 per cent water and 1.5 per cent of the Twitchell reagent. The latter 
is prepared by allowing an excess of sulphuric acid to act on a solution of 
naphthalene (or other aromatic hydrocarbon) in oleic acid, which results in 
the production of a body having the general composition : ^ 

CioHexX Vr r\ Naphthalene-sulfo-stearic acid. 
\Ui8-ti35U2 

It is advisable to introduce a small percentage of free fatty acids to start 
the hydrolysis which otherwise takes a little time to begin. The material 
is steamed for twenty-four hours, whereupon a small quantity (0.1 to 0.2 
per cent) of 60° Baume sulphuric acid is added to break up the emulsion 
and permit the fatty acids to rise to the surface and the glycerol to pass 
into the aqueous liquor below. About 0.05 per cent of barium carbonate 
is finally added to neutralize the mineral acid. 

The resulting fatty acids are dark in color and must be distilled. This 
is usually affected after a preliminary treatment with concentrated sul- 
phuric acid as in method (6) to increase the yield of stearin, which is of 
special importance when the product is to be used for manufacturing 
candles. The yield is the same as obtained from the saponification or 
mixed process respectively, depending upon the exact method of treatment. 

A new reagent has recently appeared on the market under the name 
" kontakt," discovered by the Russian chemist Grigori Petroff,^ consist- 
ing of aromatic sulpho derivatives prepared from Baku mineral oils 
(specific gravity 0.879) by means of fuming sulphuric acid. It is supposed 
to have the general formula CnH2n-9-S03H, and is marketed in the form 
of the soda or potash salts to secure a more concentrated product. This 
catalyzer does not darken the fats or oils, as was the case with the earlier 
reagent, and hence it becomes unnecessary to distil the resulting free fatty 
acids in making high-grade soaps, unless the raw fats or oils are themselves 

»U. S. Pat. 601,603 of Mar. 29, 1898, to Ernest Twitchell. 

2 French Pat. 448,207 of Aug. 31, 1912; U. S. Pat. 1,233,700 of Jul. 17, 1917, to Grigori Petroff. 



324 ASPHALTS AND ALLIED SUBSTANCES 

very dark in color. With high grade stock, J to 1 per cent of kontakt 
is used, and with low grade materials, such as yellow or brown greases, 
1 to 2 per cent.^ 

This process is adapted particularly for treating raw materials of 
low quality, including " greases," which do not readily yield to method (a). 

(e) Hydrolysis by Means of Ferments. This method is also meeting 
with some favor, as it produces a large yield of glycerin uncontaminated 
with salt or other solids difficult of separation. Many soap manufac- 
turers accordingly hydrolyze their stock by means of ferments to separate 
the glycerin, and then saponify the resulting fatty acids with sodium 
carbonate either direct or after first purifying them by steam distillation. 

The ferment is derived from the castor plant by grinding the decorti- 
cated castor beans with water and filtering through cloth, whereupon a 
white creamy filtrate is obtained which is set to one side and allowed to 
ferment spontaneously. The ferment which rises to the surface, is 
skimmed off and used while fresh. It is composed of a thick creamy 
substance containing approximately 38 per cent of fatty acids derived 
from castor oil, 58 per cent of water and 4 per cent of an albuminoid sub- 
stance containing the active material. 

The fat or oil to be treated is mixed with 40 per cent water, 5 to 8 
per cent of the ferment and 0.2 per cent of manganese sulphate in a lead- 
lined vessel equipped with a steam coil and a perforated compressed-air 
pipe. Heat is then turned on, and the temperature maintained 2 to 3° C, 
above the melting-point of the fat or oil. The mass is agitated by air intro- 
duced through the perforated pipe and the treatment continued one to 
three days until the hydrolysis is complete. Sufficient steam is then 
turned on to bring the mass to a temperature of 80 to 85° C, whereupon 
0.30 to 0.45 per cent of 50 per cent of sulphuric acid is stirred in by air. 
This breaks up the emulsion, the clear fatty acids rising to the top 
and the aqueous liquor containing the glycerin settling to the bottom. 

When the separated fatty acids are pale in color they may be saponi- 
fied directly for manufacturing soaps. Where dark-colored fats, oils 
or greases have been employed, which result in the production of dark- 
colored fatty acids the mass is distilled with steam, whereupon the fatty- 
acid pitch is obtained as residue. Candle stock may also be produced 
by subjecting the purified fatty acids to a low temperature and filtering, as 
described previously. 

It is, of course, understood that when the crude oils or fats (triglycer- 
ides) or the free fatty acids derived from them (by any of the foregoing 

i"A New Catalytic Reagent for Splitting Glycerin from Fats and Oils," by R. E. Divine, 
Am. Perfumer, 11, 377, 1917. 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 325 

processes of hydrolysis) are saponified directly with sodium carbonate 
(soda ash), no fatty-acid pitch is produced. 

Refining Vegetable Oils by Means of Alkali. Most vegetable oils 
intended for edible purposes, whether the}^ are to be used for salad oils, 
lard substitutes, margarine manufacture, or directly for cooking oils and 
shortening, are first treated with caustic soda for the purpose of removing 
free acids, coloring matter, albuminous material, resins, etc. The oils 
chiefly treated are cotton-seed, corn, soya be?,n, cocoanut and peanut 
oils. 

(a) Refining Cotton-seed Oil. Crude cotton-seed oil when obtained 
fresh from the seed varies in color from reddish brown to almost black. 
This is due in part to the coloring matter, which is a dark resinous substance 
capable of combining with caustic soda forming a water-soluble salt, 
also albumin and pectin bodies. The method of refining the oil consist3 
in agitating it with varying quantities of caustic soda solution, the strength 
of which will range from 1.10 to 1.20 specific gravity, according to the 
percentage of free fatty acids present and the practice of the individual 
refiner. The agitation is effected by mechanical stirrers in large tanks 
provided with heating coils. The quantity of alkaline liquor added is 
determined by careful laboratory test and run in through perforated pipes. 
The effect of the alkali is first to darken the oil and apparently thicken it. 
After a short time small flakes begin to separate and heat is then applied. 
As the temperature increases, the flakes become larger, owing to the soap 
softening and running together. When the right point is reached, at 
temperatures varying from 100 to 130° F., steam and agitation are shut 
off and the soap drops to the bottom of the kettle, forming a mucilaginous 
mass, varying in color from yellow to brown through all shades of green 
and red. This material is known as the " foots." The clear light yellow 
oil which is pumped off the foots is then refined further for edible purposes. 
Cotton-seed oil purified in this manner is known to the trade as " summer 
yellow oil." When used in making lard substitutes it is bleached with 
fuller's earth and then deodorized, generally by the use of steam. Salad 
oil is obtained by chilling the summer yellow oil so as to crystaUize out 
the palmitin which is separated by pressing or filtering. 

In the United States alone the annual production of cotton-seed foots 
amounts to approximately half a million barrels valued at two million 
dollars. The foots vary in gravity from 0.97 to 1.04, averaging about 
1.00. They contain the soda salts of the coloring matter, the soda soaps 
of any free fatty acids present in the cotton-seed oil (30 to 45 per cent) 
the coagulated albumin (8 to 12 per cent), phytosteryl (see p. 549), anc 
varying quantities of mechanically entrained cotton-seed oil (triglycerides). 



326 ASPHALTS AND ALLIED SUBSTANCES 

Cotton-seed foots are sold on the basis of '^50 per cent fatty acid." 
As a matter of fact they contain between 35 and 65 per cent, averaging 
about 45 per cent. A representative sample contained : ^ 

Fatty anhydrides (corresponding to a "50-per cent soap stock") . 48.50% 

Glycerin 3 . 98% 

Caustic soda (Na20) 3.20% 

Foreign organic matter 5 . 90% 

Coloring matter 2 . 42% 

Water 36.00% 



Total 100.00% 

The cotton-seed foots may be converted directly into soap by boiling 
up with a small excess of caustic soda and '^ salting " it out in the usual 
manner, when no pitch will be obtained. The resulting soap is known 
as " killed foots " and the dark lye containing the coloring matter and 
impurities is run to waste. A process has also been described for recovering 
a shellac-like substance from cotton-seed foots by oxidizing with hydro- 
gen peroxide in an alkaline solution and acidifying to separate the fatty 
matter. 2 

Usually, however, the cotton-seed foots are subjected to distillation. 
They are first acidified while hot with dilute sulphuric acid, whereupon a 
" black grease " containing about 90 per cent of the total fatty acids 
(calculated as oleic) rises to the surface. This is separated and subjected 
to the Twitchell or other hydrolyzing processes to break up any neutral 
fat and recover all the glycerin. The fatty acids obtained in this manner 
are equivalent to 7.5 to 8.5 per cent of the original weight of the cotton- 
seed oil used. They are subjected to vacuum distillation with super- 
heated steam to separate the pure fatty acids from the residue of fatty- 
acid pitch, variously called " cotton pitch," " cotton-oil pitch," cotton- 
seed-oil pitch," ^' cotton-stearin pitch," " cotton-seed-oil-foots pitch," 
etc. The quantity of pitch produced will range between 10 and 20 per 
cent of the weight of the crude fatty acids (black grease) distilled, which is 
equivalent to 1 to 2 per cent by weight of the original cotton-seed oil. 
The yield will depend upon the degree the oil is saponified, the amount of 
impurities present, the efficiency of the distilling apparatus and the extent 
to which the distillation is carried. 

The purified fatty acids recovered by distillation are used for manu- 
facturing soaps. The fatty-acid pitch is usually soft in consistency, 
moderately stringy and of a pale brown color when examined by trans- 
mitted light in thin layers. 

1 David Wesson, J. Soc. Chem. Ind., 26, 595, 1907. 

2Ger. Pat. 220,582 of Jun. 26, 1909, to Hermann Loeschigk. 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 327 

(6) Refining Corn Oil. Corn oil is sometimes refined by treating with a small 
proportion of caustic soda in a manner similar to the method described for cotton- 
seed oil. Upon deodorizing the refined product with superheated steam under 
reduced pressure, while heated to a temperature of 400° F., an edible product is 
obtained, used as a salad oil, also for cake and biscuit making. It may also be 
converted into a lard compound by a hj^drogenation process. The corn-oil foots 
are treated by a method similar to the one used for refining cotton-seed foots. 
A pitch is obtained known as "corn-oil pitch," possessing a comparatively high 
fusing-point, characterized by its rubber-like properties and lack of ductility. If 
the distillation is carried too far, the pitch will actually solidify in the still and 
can only be removed with great difficulty. 

Refining Refuse Greases, (a) Refining Packing-house and Carcass-rendering 
Greases. "Tallow" is the name applied to the purified solid fat or "suet" obtained 
from cattle. It is used extensively for producing soap and candle stock. The 
crude fat is first "rendered" by boiling with water in an open vessel to separate 
it from any albuminous matter or other impurities present, and then clarified by 
washing with weak brine. "Lard" is obtained by rendering the soft fats which 
surround the kidneys, intestines and backs of pigs. Tallow and lard may be used 
as such for manufacturing soaps, but for producing candles they must first be 
hydrolyzed and purified by steam-distillation. 

The waste meat scraps obtained from packing houses, also the carcasses of 
animals freed from the bones, are treated with steam in large digestors at a high 
pressure to separate the fat. When the cooking is complete, the batch is allowed 
to stand quietly to permit the grease to rise to the surface and the disintegrated 
meat-fibres to settle. The grease is skimmed off and mixed with any additional 
grease recovered from the settlings by filter-pressing. The residue is then con- 
verted into fertilizer, and the aqueous liquid used for making glue. The grease 
recovered from this process has a disagreeable odor and a dark color, and must 
be hydrolyzed and steam-distilled before it can be used for manufacturing either 
candles or soap. The residue from the steam distillation process amounting to 
between 5 and 6 per cent of the grease, constitutes a variety of fatty-acid pitch 
having a light brown color when viewed in a thin layer and great ductility (unless 
the pitch is distilled too far). A packing-house grease has been extensively marketed 
in this country under the name of "yellow grease." 

(6) Refining Bone Grease. The bones recovered from packing houses or carcass- 
rendering works are used for manufacturing glue, bone-black (used for decolorizing 
petroleum distillates, see p. 308), and fertilizer. Bones from the head, ribs and 
shoulder-blades contain 12 to 13 per cent of fat, whereas the large thigh bones 
('marrows") contain 20 per cent. The fat is extracted by breaking up the bones 
into small fragments and then either: 

(1) Treating with steam in an autoclave under a pressure of 2 to 3 atmospheres, 
whereupon a portion of the fat separates and floats to the surface, the gelatin 
or glue goes into solution, and the mineral ingredients (calcium phosphate, etc.) 
remain as residue. From 8 to 9 per cent of fat (based on the dry weight of the 
bones) is recovered in this manner. 

(2) Extracting the dried bones with a volatile solvent such as benzine, carbon 
tetrachloride, or benzol in a suitable apparatus. A much larger percentage of fat 
is extracted in this manner, but the cost of operation is higher, due to unavoidable 
losses of solvent, and the odor of the product is very strong. 



3^8 ASPHALTS AND ALLIED SUBSTANCES 

In either event the extracted bone fat is first hydrolyzed by any of the fore- 
g )ing methods and then steam-distilled, whereupon a variety of fatty-acid pitch, 
known as "bone-fat pitch" is recovered as residue, amounting to 5 to 6 per cent 
by weight of the bone-fat. The product may be used for manufacturing soap, 
^>r after cooling and filtering, the "stearin" may be converted into candles, and 
the "olein" either used for manufacturing soap or else marketed as such for "wool 
oils." 

(c) Refining Garbage and Sewage Greases. The average city garbage as collected 
contains: 

Water 70-80% 

Grease . 3-4% 

Tankage 10-20% 

Tailings (rubbish) 3- 6% 

It is treated in a manner similar to that used for working up the refuse from 
packing houses and carcass-rendering establishments, namely by boiling in large 
digestors holding 8 tons for six hours under a pressure of 70 to 80 lb. (Arnold- 
Egerton System).^ This reduces the material to a pulpy mass, which is filter-pressed 
to remove the water and grease. The residue, known as "tankage," is dried and 
ground for use as fertilizer. The filtrate is allowed to stand, whereupon the grease 
rises to the surface and is skimmed off. The grease when dehydrated, has a dark 
brown color. It is hydrolyzed to separate the glycerin, and the resulting fatty 
acids purified by steam-distillation to render them suitable for manufacturing 
soaps and candles. The residue, known as "garbage pitch," amounting to 5 to 
7 per cent by weight of the garbage, has a dark color when viewed in a thin 
layer, and is quite susceptible to temperature changes. 

Sewage also carries a proportion of grease which is now often being recovered, 
especially in large cities. The sewage is first run into large tanks, where the 
solid matter known as "sludge" settles to the bottom. T'he precipitation may be 
accelerated by adding a small percentage of slaked lime. After drawing off the 
liquor, the sludge is treated with a small quantity of sulphuric acid to break up 
any insoluble soaps, and then boiled in large digestors under pressure to hydroHze 
the fats, and enable the grease to separate. The residue is dried and used as fer- 
tilizer. The grease is dehydrated, then hydrolyzed and finally distilled with super- 
heated steam, yielding about 25 per cent of a fatty-acid pitch known as "sewage 
pitch." The characteristics of this are similar to those of garbage pitch. The dis- 
tillate contains about 50 per cent of liquid olein and 50 per cent of solid stearin 
melting at about 113° F.^ 

(d) Refining Woolen-mill Waste. Olive oil, lard oil, neat's-foot oil, saponification 
olein (or saponified olein) and distillation olein (or distilled olein) are sold under 
the names " wool oils " or " cloth oils," and used in woolen mills for lubricating 
the wool before spinning into yarn, or for oiling old woolen rags before grinding and 
" pulling " in the manufacture of " shoddy." One of the perquisites of the wool 
oils is that they shall have no tendency to dry or oxidize, and they must also be 

i"City Refuse and its Disposal," H. de B. Parsons, J. Soc. Chem. Ind., 27, 376, 1908; "Col- 
lection and Final Disposition of City Wastes by the New York Department of Street Cleaning," 
Edward D. Very, J. Soc. Chem., Ind., 27, 378, 1908; "Garbage and Rubbish Disposal in Los 
Angeles," by S. B. Simons, Munic. J., 38, 799, 1915. 

2 "The Utilization of Sludge from Town Sewage as a Source of Fat," D. Holde, Seifensieder- 
Ztg., 41, 1151, 1915. 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 329 

easily removable on boiling the finished woolen goods or shoddy with a solution oY 
soap or sodium carbonate. The presence of hydrocarbons, even in small quantities 
is objectionable, as they tend to prevent the removal of the wool oils during the 
scouring process. 

After the goods are scoured, the liquid is mixed with freshly slaked lime which 
serves to precipitate the soaps. The curds are settled out and separated, then acid- 
ified" with dilute sulphuric acid to separate the free fatty acids, which are skimmed 
ofT and filtered to remove any dirt. The product known as " fuller's grease," 
" seek oi /' or " magma oil," is distilled with steam, whereby the wool oils are 
recovered, and a residue of fatty-acid pitch obtained, amounting to 10 per cent by 
weight of the grease; known as " fuller's-grease pitch," or " seek-oil pitch." 
This will vary in its properties depending upon the raw materials entering into the 
composition of the original wool oils. 

Treatment of Wool Grease. Wool grease, known also as "wool wax," or 
" wool degras " represents the oily material naturally present in sheep's wool, and 
differs entirely from the so-called " wool oil " discussed previously. Wool grease 
is in reality an animal wax, as it contains no glycerin or glycerides whatsoever. 
It is extracted by boiling the cut wool with an alkaline soap solution or sodium 
carbonate. Formerly volatile solvents were used for this purpose, but the method 
is no longer practiced. After boiling with soap or sodium carbonate, the liquor is 
acidified with sulphuric acid, whereupon the grease rises to the surface and is 
skimmed off. Dehydrated wool grease melts between 86 and 104° F. and contains 
approximately 55-60 per cent fatty acids, also 40-45 per cent higher alcohols (un- 
saponifiable). 

Wool grease is treated in various ways, and among others by a direct process of 
distillation with superheated steam without previous hydrolysis ^ (as the waxes 
present are not amenable to such treatment) whereby the following portions are 
recovered : 

(1) A light oil composed mainly of hydrocarbons. 

(2) A heavier oil which on coohng separates into a liquid and a solid portion. 
This is thereupon cooled and filter-pressed to separate the olein (known as " dis- 
tDled-grease-olein " or " degras oil "), which is used as a leather or wool oil, from 
the stearin (known as " degras stearin "), which is used in the soap industry or 
as a leather " stuffing grease." The olein consists of 50 per cent free fatty acids 
and 50 per cent unsaturated hydrocarbons and cholesterol. The stearin carries 
70 per cent cholesterol and 30 per cent free fatty acids. 

(3) A residue of fatty-acid pitch known specifically as " wool-grease pitch," 
" wool-fat pitch," " wool pitch " or " cholesterol pitch." The pitch is distin- 
guished by its high ductility and susceptibility factor, the large proportion of 
unsaponifiable constituents present and the fact that it yields a decided cholesterol 
reaction (see page 549). 

The yields are approximately 10 per cent light oil, 50 per cent olein, 30 per 
cent stearin and 10 per cent fatty-acid pitch. 

The reactions which take place during its distillation are quite complicated. 
Some of the esters break up into free fatty acids and hydrocarbons thus: 

C15H31CO • OC16H33 = C15H31CO • OH-I-C16H32. 

Cetyl palmitate Palmitic Acid Cetin 

lU. S. Pat. 896,093 of Aug. 18, 1908, to Carleton Ellis. 



330 ASPHALTS AND ALLIED SUBSTANCES 

Similarly the higher alcohols and cholesterol distil partly as such and also partly 
decompose into hydrocarbons. ^ 

Physical and Chemical Properties of Fatty acid Pitches. Fatty-acid 
pitches vary considerably in their physical and chemical properties, depend- 
ing upon the following circumstances: 

(1) The nature of the fat or oil from which the fatty acids are derived. 
If these contain low melting-point fatty acids, the fatty-acid pitch will be 
soft in consistency, provided the distillation has not been carried too far 
(see p. 320). On the other hand if high-melting point fatty acids pre- 
dominate, the fatty-acid pitch wil be semi-solid to solid in consistency. 

(2) The proportion of neutral fats or oils present in the fatty-acid 
mixture, which will prove to be the case if the process of hydrolysis is 
not carried to theoretical completion. Since the neutral fats or oils (tri- 
glycerides) do not distil with superheated steam, they concentrate in the 
fatty-acid pitch, and are very apt to decompose into hydrocarbons (un- 
saponifiable) if the distillation is carried too far (see p. 319). If the dis- 
tillation is stopped at a point without decomposing the neutral fats or 
oils, the value of the fatty-acid pitch is enhanced by their presence, as they 
are more stable and weather-resistant than the fatty-acids themselves. 

(3) The extent to which the distillation is carried and the tempera- 
ture at which it is performed. If distilled too far or at too high a tem- 
perature, the fatty acids decompose in the presence of steam, first into 
hydroxy acids, which in turn break down into lactides, unsaturated prod- 
ucts and lactones in the following manner: - 

(a) a-hydroxy acids are converted into lactides in accordance with the 
following reaction- 

R 
I 

R-CH-I OH H| OCO RCH-O-CO o CO 

I ■ + I -> I I or I I . 

CO.O|H HOi-CH.R COOCHR CO O 

^ \CH^ 

I 
R 

(6) jS-hydroxy acids become converted into unsaturated products as 

follows: 

(« («) 
R.CH2CH.COOH -> R.CH2:CH.C00H. 



OH H 



» Donath and Margosches, Chem. Rev. Fett-Harz-Ind., 12, 194, 1904; Chem. Ind., 27, 220, 1904. 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 331 

(c) 7 and 5 hydroxy acids are transposed into cyclic esters of the nature 
of 7 and 5 lactones respectively, in the following manner: 



(7) (« (a) (a)CH2-C0 

R.CH2CH2CH2CO _^ I 



o 



and 



OH HO (/3)CH2-CH.R 

(7) 

i^l M M M .. ck-co 



R.CH2CH2CH2CH2C0 



(/3) CH2<' '>0 



I ^ ^^^ "^""^\ 



OH H|0 CHo-CH.R 

(t) (5) 

It follows therefore that the fatty-acid pitches contain free fatty acidS; 
their lactones (anhydrides), undecomposed glycerides (neutral fats or 
oils), condensation products of unknown composition, hydrocarbon 
decomposition products; and in the case of fatty-acid pitches derived 
from wool grease, we find cholesterol and higher alcohols.^ 

The presence of hydrocarbon decomposition products is evidenced 
largely by the color of the pitch when examined in a thin layer. If these 
are present, the pitch will be a black, otherwise it will have a rich brown 
color. The percentage of saponifiable constituents present in the fatty- 
acid pitch is a criterion of its quality. The larger the percentage, the 
better the quality from the standpoint of weather-resistance. Fatty- 
acid pitches of the optimum quality contain not less than 90 per cent of 
saponifiable constituents. They are as weather resistant as any bitu- 
minous substance. The smaller the percentage of saponifiable constituents 
in the pitch, the less weather-resistant it will prove to be. 

In recent years there has been a tendency to remove more and more 
of the saponifiable ingredients from the fatty-acid pitches, in view of the 
high price commanded by the fatty acids, and also because of improvements 
effected in the distillation process. The author has examined fatty-acid 

1 " Stearin Pech," by E. Donath and R. Strasser, Chem. Zeit., 17, 1788, 1893; "Die Unter- 
scheidung und chemische Natur von dunkeln pechartigen Riickstanden der Distillation von Erdolen, 
Fetten und Fettsauren," D. Holde and J. Marcusson, Mitth. konigl. techn. Versuchanst. von 
Berlin, 18, 147, 1900, also Chem. Rev. Fett-Harz-Ind., 7, 2, 1900; " Zur Unterscheidung der 
Asphalte," B. M. Margosches, Chem. Rev. Fett-Harz-Ind., 11, 148, 1904; " Examination of Pitches," 
by E. Donath and B. M. Margosches, Chem. Ind., 27, 220, 1904; " Notizen iiber Stearinpeche," 
E. Donath, Chem. Rev. Fett-Harz-Ind., 12, 42, also 73, 1905; " Untersuchung der Kohlenwasser- 
stoflfole und Fette," D. Holde, Berlin, p. 281, 1913; "Detection of Petroleum Pitch in Fat Dis- 
tillation Residues," J. Marcusson, Mitt. kgi. IMaterialsprufungsamt, 30, 18G, 1913; " Stearin Pitch," 
by H. Mayer, Seifensieder Z., 41, 394, 1914; " Chemical Technology and Analysis of Oils, Fats 
and Waxes," by Dr. J. Lewkowitsch, 5th Edition, London, 1915. 



332 ASPHALTS AND ALLIED SUBSTANCES 

pitches containing as high as 98 per cent unsaponifiable constituents. 
These appear glossy black in color and almost opaque in a thin layer, and 
therefore find a ready use in the manufacture of cheap lacquers and japans, 
not intended for exposure out of doors. 

All fatty-acid pitches are converted in a more or less infusible and 
insoluble mass upon exposure to the weather for a long period, or upon 
heating a short time to a temperature of 250 to 350° C. in contact with air. 
This is equally true whether or not unsaponifiable constituents are present, 
and makes this class of pitches especially valuable for manufacturing, 
baking japans and varnishes.^ They are also converted into insoluble 
and infusible substances by heating with sulphur.^ Blowing with air at 
high temperatures rapidly increases their fusing-point and at the same 
time tends to convert them into the insoluble modification.^ 

Fatty-acid pitches containing a large proportion of saponifiable con- 
stituents show an extremely low susceptibility factor, in fact lower than 
any other class of bituminous materials. Conversely fatty-acid pitches 
in which the unsaponifiable constituents predominate are apt to have 
quite a high susceptibility factor. 

In general, the various classes of fatty-acid pitch are characterized by 
the following predominating physical properties, assuming that they 
have been carefully prepared and neither overheated nor distilled too 
far, viz.: 

Fatty-acid pitches made from lard are usually very ductile with a low susceptibility 
factor. 

Fatty-acid pitches made from tallow are generally hard, lacking in ductility with a 
low susceptibility factor. 

Palm oil pitches are hard, lacking in ductility, with a moderately high susceptibility 
factor. 

Cotton-seed-foots pitch is usually soft, of moderate ductility having a low suscep- 
tibility factor. 

Corn-oil-foots pitch is extremely rubbery, shows little ductility and has an exceed- 
ingly low susceptibility factor. 

Packing-house pitch is ductile and has a low susceptibility factor. 

Bone-fat pitch lacks ductility and has a moderately high susceptibility factor. Its 
color in a thin layer and streak are black. 

Garbage and sewage pitches are ductile with a high susceptibility factor. Their 
color in a thin layer and streak are usually black. 

Wool-grease pitch is ductile and has an extremely high susceptibility factor. Its 
color in a thin layer and streak are usually black. 

lU. S. Pat. 842,615 of Jan. 29, 1907, to Paul Boerche; Ger. Pat. 217,026 of 1905 to Vogelsang; 
also Eng. Pat. 3345 of 1906 to Connolly. 

2 U. S. Pats, to Griscom, p. 295; also Ger. Pats. 77,810 to L. Baarnhielm and A. Jernander; 
225,911 to Malchow. 

sGer. Pat. 208,378 of Sept. 13, 1905, to Otto Schreiber. 



teristics: 




(Test 


1) 


(Test 


la) 


(Test 


26) 


(Test 


3) 


(Test 


4) 


(Test 


5) 


(Test 


6) 


(Test 


7) 


(Teat 


9c) 


(Test 


9d) 


(Test 10) 


(Test 13) 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 333 

Fatty-acid pitches (referring to all types) comply with the following charac- 

Color in mass Dark brown to black 

Homogeneity to the eye at 77° F Uniform to gritty 

Homogeneity under microscope Uniform to lumpy 

Appearance surface aged indoors one week Bright 

Fracture None to conchoidal 

Lustre Bright 

Streak on porcelain Light yellow, brown to black 

Specific gravity at 77° F 0.90-1.10 

Consistency at 77° F 0-40 

Susceptibility factor 8-40 

Ductility Variable 

Odor on heating Characteristic: " fatty " 

Note. If heated with powdered potassium bisulphate, an odor of acreolin will be evolved 
due to the decomposition of the glycerin present. 

(Test 15a) Fusing-point (K. and S. method) 35-225° F. 

(Test 156) Fusing-point (B. and R. method) 50-245° F. 

(Test 16) Volatile matter 500° F., 4 hrs 0.5-7.5% 

Note. In nearly all cases, a skin will form over the surface of the pitch during the deter- 
mination of the volatile matter. This is characteristic. Certain fatty-acid pitches, especially 
those containing a large percentage of saponifiable constituents, often toughen up and solidify 
to a rubber-like mass during this test. 

(Test 17a) Flash-point '. 450-650° F." 

(Test 19) Fixed carbon 5-35% 

(Test 21a) Solubility in carbon disulphide 95-100% 

(Test 216) Non-mineral matter insoluble 0-5% 

(Test 21c) Mineral matter 0-5% 

(Test 22) Carbenes 0-5% 

(Test 23) Solubility in 88° naphtha 80-100% 

(Test 28) Sulphur 0% 

(Test 30) Oxygen 2-10% 

(Test 33) Paraffine Trace 

(Test 34) Saturated hydrocarbons 0-5% 

(Test 35) Sulphonation residue 0-5% 

(Test 37) Saponifiable constituents 5-98% 

(Test 37a) Acid value (including lactone value) 2-100 

(Test 376) Ester value 40-125 

(Test 37d) Saponification value 60-200 

(Test 39) Unsaponifiable matter 2-95% 

(Test 39a) Hydrocarbons in unsaponifiable matter.... 90-100% 
(Test 396) Higher alcohols (cholesterol) in unsaponi- 
fiable matter 0-10% 

(Test 40) Glycerol Trace-2 . 5% 

(Test 41) Diazo reaction No 

(Test 42) Anthraquinone reaction No 

(Test 43) Liebermann-Storch reaction Yes in the case of the wool 

grease pitches only 

Table XXVIII contains the results of the examination of representative samples of 
fatty-acid pitch by the author: 



334 



ASPHALTS AND ALLIED SUBSTANCES 

TABLE XXVIII.— CHARACTERISTICS OF 



Test. 



Physical Characteristics: 

Homogeneity to eye at 77° F 

Homogeneity under microscope 

Appearance surface aged seven days. 

Fracture 

Lustre 

Streak 

Specific gravity at 77° F 

Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

Susceptibility factor 

Ductility in cms. at 115° F 

Ductility in cms. at 77° F 

Ductility in cms. at 32° F 

Tensile strength in kg. at 115° F. . . 
Tensile strength in kg. at 77° F.... 
Tensile strength in kg. at 32° F . . . 



Heat Tests: 

Odor on heating 

Fusing-point deg. F. by K. and S. method 
Fusing-point deg. F. by B. and R. method 
Volatile 500° F. in four hours, per cent . . . 

Character of residue 



Flash-point deg. F 

Fixed carbon, per cent. 



Solubility 
Soluble in carbon disulphide .... 
Non-mineral matter insoluble . . . 

Mineral matter 

Carbenes 

Soluble in 88° naphtha 



Tests: 



Chemical Tests: 

Sulphur , 

Paraffine , 

Sulphonation residue 

Acid value 

Lactone value 

Ester value 

Saponification value 

Unsaponifiable matter 

Hydrocarbons in unsaponifiable matter . . . 
Higher alcohols in unsaponifiable matter. 
Glycerol 



From Lard. 



Homog. 
Homog. 
Bright 



Yellow 

0.972 

0.0 

0.7 

8.2 
18.3 


42 
75 

0.0 

0.0 

0.75 



Fatty 

44.5 

57 

2.6 

Little 

Change 

452 

5.2 



100.0 
0.0 
0.4 
0.0 

100.0 



0.0 

0.0 

0.0 

17.6 

63.2 

86.4 

167.2 

0.5 



4.7 



Homog. 
Homog. 
Bright 



Yellow 
0.980 
0.0 
1.3 
9.8 

16.7 


36 

88 
0.0 
0.05 
0.95 



Fatty 

59 

74 
3.0 

Little 
Change 
525 

11.2 



100.0 
0.0 
1.4 
0.0 

100.0 



0.0 

0.3 

65.0 

79.8 

144.8 

5.5 

95.0 

5.0 



FATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 



335 



TYPICAL FATTY-ACID PITCHES. 







From 












From 










From 


Packing 


From 


From 


From 


From 


Corn 


From 


From 




House 


Bone- 


Garb- 


Sew- 


Cottonseed- 


Oil 


Palm 


-oil. 


Wool- 




Tallow. 


Refuse. 


fat. 


age. 


age. 


oil Foots. 


Foots. 






grease. 


Homog. 


Homog. 


Homog. 


Homog. 


Homog. 


Gritty 


Homog. 


Homog. 


Gritty 


Homog. 


Homog. 


Gritty 


Homog. 


Homog. 


Homog. 


Gritty 


Gritty 


Lumpy 


Lumpy 


Homog. 


Lumpy 


Homog. 


Gritty 


Lumpy 


Bright 


Bright 
Conch. 
Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Bright 


Dull 

Conch. 

SI. dull 


Bright 
Conch. 
Bright 


Bright 


Brown 


Brown 


Brown 


Black 


Black 


Black 


Yellow 


Brown 


Brown 


Brown 


Black 


Black 


1.000 


1.060 


1.003 


1.036 


1.063 


1.011 


0.992 


0.955 


0.998 


1.042 


1.087 


1.O20 


1.5 


11.3 


0.6 


2.4 


2.6 


2.9 


0.0 


1.1 


7.2 


9.3 


11.7 


0.0 


5.8 


23.2 


6.3 


7.9 


11.7 


30.0 


2.7 


5.1 


15.8 


24.7 


35.2 


4.2 


15.2 


52.0 


15.7 


55.4 


60.1 


48.3 


14.1 


16.5 


25.1 


56.5 


82.0 


32.8 


12.5 


22.3 


15.6 


41.9 


40.5 


33.9 


19.7 


15.3 


8.5 


29.5 


41.0 


35.8 


2.5 


18.5 


23. 


18. 


72.5 


52. 


8.5 


31. 


5. 


35.5 


25. 


15. 


28.5 


4. 


81.5 


5. 


60. 


15. 


19. 


26.5 


2. 


2. 


0.5 


47.5 


18. 


0. 


20. 


0. 


0. 


0.5 


28.5 


10. 


0.5 


0. 





31 


0.05 


1.75 


0.0 


0.05 


0.50 


0.25 


0.0 


0.05 


0.75 


1.00 


2.20 


0.0 


0.20 


3.10 


0.40 


0.30 


1.25 


1.10 


0.10 


0.5 


1.55 


2.2 


5.00 


0.25 


2.35 


6.2 


3.25 


4.70 


6.2 


8.0 


2.30 


4.2 


5.4 


9.5 


11.25 


1.05 


Fatty 


Fatty 


Fatty 






Fatty 


Fatty 


Fatty 


Fatty 


Fatty 


Fatty 


Fatty 


110 


182 


97 


126.5 


142 


134 


71.5 


101 


210 


161.5 


172 


91.5 


130 


202 


115 


144 


162 


151.5 


92 


120 


235.5 


186 


193 


108.5 


5.0 


1.2 


1.7 


0.5 


0.6 


0.55 


4.2 


0.38 


0.25 


3.5 


1.2 


7.2 


Little 


Little 


Little 


Little 


Gelat. 


Gelat. 


Gelat. 


Gelat. 


Gelat. 


Much 


Little 


Little 


Change 


Change 


Change 


Change 


Change 


Change 


Change 


Change 


486 


482 


510 


575 


590 


540 


635 


525 


580 


462 


504 


460 


12.0 


18.4 


12.6 


19.4 


33.5 


18.3 


10.8 


9.2 


8.2 


26.2 


34.0 


30.6 


100.0 


98.5 


100.0 


97.7 


98.2 


98.2 


99.8 


97.5 


97.3 


98.2 


96.2 


98.8 


0.0 


2.1 


0.0 


0.0 


0.7 


1.7 


0.2 


0.4 


2.0 


0.8 


3.8 


0.5 


0.5 


1.3 


2.0 


0.3 


0.35 


0.8 


1.4 


0.3 


0.5 


1.2 


1.3 


1.1 


0.0 


0.1 


0.0 


0.1 


0.4 


1.1 


0.0 


0.0 


0.2 


2.1 


4.3 


0.0 


98.0 


86.7 


100.0 


94.6 


88.3 


95.2 


100.0 


92.1 


96.4 


92.0 


82.2 


99.0 




0.0 
0.0 


0.0 


0.0 
0.0 


0.0 
0.0 


0.1 


0.0 


0.0 
0.0 


0.0 


0.0 
0.2 






0.0 


0.3 


0.0 




44.1 


3.7 
23.5 


4.0 
20.2 


2.5 


3.0 


0.0 
60.5 




0.5 


1.2 
46.5 






81.95 


13.4 


36.5 


97.55 


112.0 


74.1 


39.5 


103.5 




95.4 






92.9 


53.9 


88.7 


179.5 


156.1 


97.6 


59.7 


106.0 


120.4 


155.9 


151.0 


172.0 


139.4 


67.3 


125.2 


1.0 


15.2 


5.0 


98.0 


97.0 


7.0 


2.0 


4.6 


2.7 


6.0 


75.0 


60.6 




97.0 




93.6 


91.7 


90.5 


95.0 






96.0 




90.0 





3.0 




6.4 


8.3 


9.5 


5.0 






4.0 




10.0 





0.0 








0.55 


0.8 


2.35 











336 ASPHALTS AND ALLIED SUBSTANCES 

According to Marcusson ^ the saponification value of fatty-acid pitches never 
runs below 33, and in the majority of cases exceeds 100, whereas the saponification 
value of petroleum asphalts does not exceed 21. A. R. Lukens ^ reports that the 
saponification value of fatty-acid pitches ranges from 45 to 100, and in the case of 
petroleum asphalts from 5 to 18. 

Fatty-acid pitches are also distinguished from asphalts by the small percentage 
of sulphonation residue, and the absence of sulphur. 

According to Donath and Margosches (loc. cit.) wool-grease pitch may be 
identified by boiUng the material with alcoholic potash, and then filtering the hot 
liquid. A fairly abundant precipitate will form in the filtrate on cooling, which 
will give the cholesterol reaction. (Test 43.) 

The author has found the lineal coefficient of expansion of fatty-acid pitches for 
1° F. (length = 1) to average 0.00023. 

Fatty-acid pitches flux satisfactorily with mineral waxes, native and pyrogenous 
asphalts, tars and pitches. They also flux satisfactorily with gilsonite and glance 
pitch, but not with grahamite. 

The following figures indicate that the hardening (toughening) of fatty-acid 
pitches on exposure to the weather is due to oxidation. A sample of soft fatty-acid 
pitch (the first in Table XXVIII) was melted and poured into a shallow glass 
dish, forming a layer exactly 1 millimeter thick. This was exposed out of doors 
for one year in a dust-free receptacle protected from the direct action of the weather, 
and the following increases in weight noted: 

After 1 month gained 0.62% After 7 months gained 4.20% 

2 2.52% 8 4.27% 

3 3.27% 9 4.30% 

4 3.50% 10 4.38% 

5 3.86% 11 4.42% 

6 4.12% 12 4.46% 

The original pitch was soft and semi-liquid, but after exposure for one year it 
hardened to a tough, leathery mass. The original fusing-point was 44^° F. (K. 
and S. method), and at the end of the year 185° F. 



BONE TAR AND BONE-TAR PITCH 

In the production of bone tar and bone-tar pitch the crude bones are 
first steeped in a 1 per cent solution of brine for three to four days, to 
separate the fibrous matter. They are then degreased by one of the 
following methods: 

(1) Boiling the bones with water in open vessels; 

(2) Boiling with water in closed tanks under a pressure of 10 lb.; 

(3) Extracting the bones with a solvent (usually a petroleum distillate 
boiling at 100° C.) and removing the last traces of solvent from the bones 

1 " The Composition and Examination of Residues Obtained from Fat Distillation," Z. angew. 
Chem., 24, 1297, 1911. 

2 " Distinguishing between Petroleum Residuums and the Various Fat Pitches," The Chemist- 
Analyst, 20, 3, 1917. 



PATTY-ACID PITCH, BONE TAR AND BONE-TAR PITCH 337 

by blowing in live steam. The degreased bones are then treated to extract 
the glue by again subjecting the bones to the action of live steam for a 
lengthy period under a pressure of 15 to 20 lb. in an upright cylindrical 
boiler with a false bottom. The glue gradually leaches from the bones, the 
quantity extracted depending upon the duration of the treatment. When 
it is desired to convert the bones into '^ bone charcoal " (used for the puri- 
fication of petroleum distillates and paraffine wax, as described on p. 308), 
only one-half of the gelatinous matter is extracted from the degreased bones, 
whereupon the water is drained off and the bones allowed to air-dry. The}^ 
are then distilled destructively in horizontal cast-iron retorts, the distillate 
being condensed, and the permanent gases consumed under the retort. 
The distillate consists of an alkaline aqueous liquor containing ammoniacal 
bodies, and a tarry layer known as " bone tar," " bone oil " or '' Dippel oil." 
The residue remaining in the retort, known as " bone charcoal " or '' animal 
charcoal " is removed while still hot, and transferred to an air-tight vessel 
in which it is allowed to cool. It is then passed through grinding mills 
and sieved. The bone charcoal is composed of approximately 10 per cent 
of carbon, 75 per cent of calcium phosphate, the balance consisting of 
various other mineral ingredients and moisture. 
The following yields are obtained: 

Non-condensable gases 10-15% 

Aqueous liquor » 10-15% 

Bone-tar 25-10% 

Bone charcoal 55-60% 

Total 100-100% 

The bone tar floating on the surface of the aqueous liquor is drawn off. 
It consists of fatty substances derived from the fat which escaped ex- 
traction from the bones, also derivatives of pyridine possessing a most 
disagreeable and penetrating odor, and incidentally serving to distinguish 
it from all other tars. The characteristics of bone tar are included in 
Table XXXV, page 482. 

The aqueous liquor is distilled, and the distillate caught in sulphuric acid to 
recover the ammonium compounds as ammonium sulphate. The residue is used as 
a fertilizer. 

The bone tar is subjected to fractional distillation to recover the bone-tar pitch, 
the properties of which are also embodied in Table XXXV, page 482. 

Bone-tar pitch is intermediate in its physical properties between asphalts and the 
fatty-acid pitches. It is moderately susceptible to temperature changes^ and on a 
par with higher grades of residual asphalts and inferior grades of fatty-acid pitches 
in its weather-resisting properties. 

It is produced in comparatively small quantities and cannot therefore be regarded 
as a commercial product. 



PART IV 
MANUFACTURED PRODUCTS AND THEIR USES 



CHAPTER XXIII 
METHODS OF BLENDING 

One of the most important questions which confronts the bitumen olo- 
gist is that of blending the various substances at his disposal, to produce 
mixtures best adapted for the special purposes for which they are intended. 
This requires an intimate knowledge of the nature and behavior of the 
various materials, and can only be thoroughly acquired by years of experi- 
ence. Two shipments of any given member of the bituminous family are 
likely to fluctuate widely in their physical properties and composition, 
even when procured from the identical source. A native bituminous 
substance emanating from the same deposit will vary, depending upon the 
degree of exposure and amount of metamorphosis. It has been shown 
that all native bituminous materials are in a constant state of transition, 
depending upon their age and environment. Scarcely any two deposits 
of native asphalt are alike in their properties or chemical composition. 
The same applies to petroleum, which varies in different localities and very 
often in wells side by side in the same field. 

The pyrogenous bituminous materials also show a marked variation 
in their properties, depending upon the raw materials used in their pro- 
duction and the exact conditions to which they have been subjected in 
their process of manufacture, including the temperature, length of treat- 
ment, etc. 

Bituminous materials should not therefore be compared to vegetable 
and animal fats or oils, which in the case of any one material runs fairly 
uniform in composition and physical properties. 

The consistency of the available raw bituminous materials is either 
fixed and definite, or it is controllable. All native bituminous substances 
have a predetermined consistency — in other words they are endowed by 

338 



METHODS OF BLENDING 339 

nature with certain fixed and definite physical properties, and over which 
man has no control. On the other hand, the consistency of pyrogenous 
bituminous substances, with three exceptions (i.e., wax tailings, tars and 
rosin pitch), is largely controllable, and depends upon the treatment to 
which they are subjected in the course of their production. In the majority 
of pyrogenous substances, it is a comparatively easy matter to alter their 
consistency at will, by regulating the duration of the process, its tempera- 
ture, or some other condition. In the three exceptions noted, the con- 
sistency is predetermined, and has no definite bearing upon the variable 
functions of the process. 

Table XXIX will serve to give a general idea whether the hardness and 
fusibility of the various bituminous substances are definite or controllable, 
whether the substances are naturally soft, medium or hard at room tem- 
perature; also their approximate comparative volatility, weather-proof 
properties, and efficiency in fluxing. 

In interpreting Table XXIX, it should be distinctly noted that the " Hardness 
at Room Temperature,' " Volatility," " Weatherproof Properties " and " Efficiency 
in Fluxing " are Usted in a comparatioe sense, and must not therefore be regarded 
as a definite exposition of the characteristics of any single substance, without taking 
into consideration the others cited. 

In addition to the bituminous substances, there are included three groups of non- 
bituminous substances commonly used for purposes of blending; viz., rosin, animal 
and vegetable oils and fats, and wool grease. 

In preparing mixtures of bituminous materials, the following points 
should be borne in mind: 

(1) Bituminous materials which give the diazo reaction (Test 41), 
(containing phenols), should not be mixed with bituminous substances not 
giving this reaction. In other words, native asphalts, asphaltites and pyro- 
genous asphalts should not be blended with tars or pitches (excepting 
fatty-acid pitch), since it has been found by experience that such mixtures, 
although they may melt together perfectly, are not durable or weather- 
proof. 

(2) Native and pyrogenous waxes will not remain permanently blended 
with other bituminous materials, but w411 crystallize at low temperatures, 
gradually separating from solid mixtures on standing. This manifests 
itself by the wax " sweating " from the surface. In certain cases this 
feature is desirable, since the admixture of a small percentage of wax 
imparts wax-like properties to the entire composition (see p. 347). 

(3) Grahamite does not flux with native or pyrogenous waxes, 
residual oiis derived from non-asphaltic petroleum, fatty-acid pitch or 
wool grease. 



340 



ASPHALTS AND ALLIED SUBSTANCES 



.si 

S a 



_- li O) 



^ Qi i^ .ii 






2 O 
O ^ ^ 

u o ts 






flj 03 o ° 
^ t^-r-.S 



q3 ^ 73 






tfi oj ;s ^ a^ 



i1 



o ^ 

?? -^ 
<u a 

3 03 
IK 



X ^ a X 'C a .-^ 
WHS 







2 oo 



Approximate 

Comparative 

Weatherproof 

Properties. 


bXi 
IS 


a 


proof. 

W: weather- 
proof. 

M: moder- 
ately 
weather- 
proof. 
'N: non- 
weather- 
proof. 


N 

M 

M 

Wto H 

M to W to H 

M to W to H 

WtoH 

H 


2SS2 


^ 


w 

o 

J' 


WW 
22 


Approximate 

Comparative 

Volatility. 






V: volatile. 

M: moder- 
ately 
volatile. 

N: non- 
volatile. 


> 




> 


2 


SS 






cc S K 



SWWojgWW a^^Woi «2 



«? 



aJ y=i 



:p;sll2o-Ql^§S 



og- 



Q go S Q B Q G 



m 5-:. 






^ ^ 



t3 

o 
o 



Pi .. 



C -C ^ 









OO 



i 2 



p^rt 



METHODS OF BLENDING 



341 






j3 c; 



t" P d 



. a 



= o 



(-0) (H 



« « 



T3 V* 



W rt cq fc; pq « 



Ph pq 



S 2 e 



o :: c 

•i to 
rt 2 >. 









<U rt OJ 

>< ro ><) 



-►^3 3 
ai ^ CO 



COO 
OOOOOOOCCOOOOO OOOOOOCCG 5 ° 2000 

fe f^ fin 






W lx! W ti3 



wtc 



2555^30052^:2^;?;^ 5^S55^o^^5°° 



" ►^ <H 

5 5! 
1^ 



^ w ^ 



J^ ^ ;z; :z; :z; :z; :z; :z; Ik^ ^ oS^S 



q5^o5; 



s >s 



^ _o 5 ^ ;?; ^ ^ o 5 ^ 



M^ M^ W M§ W i^ K cc^ K W co^ W cc!^ K m^ W M^ M co^ W 



9. o 



5 ^ 



Q Q Q 



o S 



-^ a 



2 a 
.. -i d 

? § ■» 



342 ASPHALTS AND ALLIED SUBSTANCES 

(4) If the bituminous material contains a percentage of '' non-mineral 
matter insoluble in carbon disulphide " (^' free carbon ''), the act of flux- 
ing with other bituminous substances, rosin, animal or vegetable oils and 
fats will only dilute this ingredient, without eliminating it. The cal- 
culated proportion will still be present in the mixture. 

(5) The percentage of carbenes may be reduced by fluxing or blending, 
as the carbenes themselves are fluxed by other bituminous substances, 
rosin, animal or vegetable oils and fats. 

(6) The thoroughness with which bituminous materials blend, may be 
ascertained by finding the fusing-point of the components, and comparing 
the calculated fusing-point of the mixture with its actual fusing-point. 
If the actual fusing-point is equal to, or greater than the calculated fusing- 
point, then the blending has been thorough. On the other hand, if the 
actual fusing-point is less than the calculated fusing-point, then the com- 
ponents do not amalgamate thoroughly. 

(7) The microscopic test may also be used to good advantage to ascer- 
tain the thoroughness with which the components blend. A separation 
of particles in the mixture is evidence that perfect amalgamation does 
not occur. 

Where the hardness and fusibihty of the bituminous substance are 
'' controllable," it is often a simple matter to continue the distillation, 
blowing, depolymerization (in the case of wurtzilite asphalt), etc., until 
a product is obtained having the desired physical characteristics. Where 
conditions permit, it is more convenient and economical to turn out a prod- 
uct of exactly the proper grade, than to flux or harden it afterwards. It 
is accordingly customary to market residual asphalts of exactly the right 
hardness and fusing-point for paving purposes, etc. Blown asphalts are 
similarly marketed in various grades, having different fusing-points (and 
hardnesses), so that the manufacturer may pick out one best adapted 
to his particular purpose. Coal-tar is likewise distilled to a predetermined 
extent to obtain pitches suitable for use as such in connection with water- 
proofing, roofing work, road purposes or briquette making, whichever 
the case may be. 

Binary Mixtures. It is not always possible to use a single bituminous 
material, since it is sometimes found that the exact characteristics required 
are lackuig, and can only be obtained by blending together two or more 
substances in suitable proportions. The simplest mixtures, containing 
two constituents, are known as " binary mixtures." In this case it is a 
comparatively simple matter to predict what the characteristics of the 
finished product will be. 

The purpose of preparing a mixture is to soften the substance and lower 



METHODS OF BLENDING 



343 



its fusing-point, to harden the substance and raise its fusing-point, to render 
the mixture less susceptible to temperature changes, effect a more perfect 
union or blending of the constituents, improve its weatherproof properties, 
increase the tensile strength, render the mixture wax-like, or unctuous to 
the feel, lessen the tendency towards stickiness, etc. 

Softening the Substance and Lowering its Fusing-point. This process is ordinarily 
known as " fluxing." When the bituminous material as it occurs naturally or results 
from a manufacturing process is too hard in consistency or fuses at too high a tem- 
perature, it is customary to mix it with a softer substance, termed a " flux," to impart 
the necessary characteristics. The fluxes may be classified in three groups as foflows: 



Group I. 


Group II. 


Group III. 


For Softening Asphaltic 
Materials and Asphaltites. 


For Softening Pitches. 


Used Indiscriminately for 
Softening Asphaltic Materi- 
als, Asphaltites and Pitches. 


Soft native asphalt. 


Medium wood-tar pitch. 


Wax tailings. 


Residual oils. 


Medium peat- and lignite-tar 


Soft and medium fatty-acid 


Soft blown asphalt. 


pitches. 


pitches.* 


Soft residual asphalt. 


Medium water-gas-tar pitch. 


Animal and vegetable oils and 


Soft sludge asphalt. 


Medium oil-gas-tar pitch. 


fats. 




Medium coal-tar pitch. 


Wool grease.* 




Medium bone-tar pitch. 





Not suitable for fluxing grahamite. 



The fluxes listed in Group II should not be used for softening asphaltic mate- 
rials and asphaltites, or those in Group I for softening pitches (excepting rosin- and 
fatty-acid pitches), for reasons already explained. The fluxes listed in Group III 
will answer satisfactorily for softening asphaltic products, asphaltites and pitches, 
without injuring their weather-resisting qualities. 

Of Group I fluxes: residual oils, soft blown asphalt and soft residual asphalt 
are ordinarily used, on account of their weather-resisting properties, their effi- 
ciency in fluxing, the absence of volatile constituents and their comparative cheap- 
ness. 

Of Group II fluxes: water-gas-tar pitch and oil-gas-tar pitch are ordinarily used 
for preparing " cut-back " coal-tar pitches for use as dust-laying oils, road surfac- 
ings, etc., as previously explained (p. 251). 

Of Group III fluxes: animal and vegetable oils or fats are most generally em- 
ployed, owing to their abundance and uniformity. They are only used in special 
cases (e.g. manufacturing certain bituminous paints, varnishes and japans, rubber 
substitutes, coating compositions for high-grade prepared roofings, etc.), in view 
of their comparatively high price, although they are without question the fluxes 
par excellence for bituminous materials. 

Hardening the Substance and Rising its Fusing-point. Where the bituminous sub- 
stance is too soft for the purpose intended, it is customary to harden it by adding one 
or more of the following materials: 



344 



ASPHALTS AND ALLIED SUBSTANCES 



Group I. 

For Hardening Asphaltic 
Materials. 


Group II. 
For Hardening Pitches. 


Group III. 

May be Used Indiscriminately 

for Hardening Asphaltic 

Materials or Pitches. 


Hard native asphalt. 

Asphaltites. 

Hard residual asphalt. 

Hard sludge asphalt. 

Hard wurtzilite asphalt. 


Hard wood-tar pitch. 

Hard peat-and lignite-tar pitches. 

Hard water-gas-tar pitch. 

Hard oil-gas-tar pitch. 

Hard coal-tar pitch. 

Hard bone-tar pitch. 


Rosin pitch. 

Rosin. 

Hard fatty-acid pitch. 

Fillers. 

Blowing with air. 

Combining with sulphur. 



Of Group I hardeners, hard native asphalts, hard residual asphalts and asphal- 
tites are most frequently used; and similarly of the Group II and Group III 
hardeners, hard coal-tar pitch and fillers respectively, are most generally employed. 
The fillers may be of vegetable or mineral origin, and will be discussed in greater 
detail later. (See p. 393.) It is not customary to harden bituminous mix- 
tures by blowing with air after they are once prepared, although this procedure 
would increase the hardness and particularly the fusing-point. All bituminous sub- 
stances may be hardened by heating with a small percentage of sulphur (see p. 
294) after the manner of vulcanization in the rubber industry. This is only used 
to a limited extent, owing to the difficulty of controlling the degree of hardening, 
also because of the fact that it tends to reduce the ductility of the product. 

Rendering the Mixture Less Susceptible to Temperature Changes. It is difficult 
to lay down any definite rules in this connection. In general, it may be stated that 
the suitable addition of the following substances will tend to make mixtures more 
resistant to temperature changes, viz.: 



Asphaltites. 
Blown asphalt. 



Wurtzilite asphalt. 
Fatty-acid pitch. 



Animal or vegetable oils and fats. 
Fillers (mineral and vegetable). 



The first three, of course, should only be used in connection with asphaltic mix- 
tures, whereas the last three are applicable either to asphaltic mixtures or pitches. 
Animal or vegetable oils and fats which have been thickened or " boiled " by heat- 
ing to a high temperature until they polymerize, are more efficient in this respect 
than oils or fats in their crude state. The effect of mineral fillers is shown in 
Table XXX (p. 346). 

Effecting a More Perfect Union or Blending of the Constituents. At times the com- 
ponents of a bituminous mixture do not amalgamate thoroughly. This is detected 
by a lack of homogeneity (Test 2), i.e., by distributing the surface and observing 
whether it becomes duller, or else by drawing out a pellet into a thin thread, and 
noting whether any dulling occurs. Certain fluxes when combined with the mixture, 
often in a small proportion, serve to overcome this tendency, and result in a more 
complete amalgamation of the components. Such fluxes in the approximate order of 
their efficiency are as follows: 



Rosin. 
Rosin pitch. 



Animal or vegetable oils and fats. 
Wax tailings. 



It will be understood that these fluxes do not influence the percentage of non- 
mineral matter insoluble in carbon disulphide (free carbon), or any dullness due to 
this constituent. 



METHODS OF BLENDING 



345 



Making the Mixture More Weatherproof. This is another question which can- 
not be decided by any hard and fixed rules, as it depends largely upon what 
materials are present in the mixture, and how badly it may lack weatherproof 
quahties. There may be cases where the bituminous substance is so deficient in 
weatherproof properties that it would be impracticable to attempt improving it, on 
account of the extremely large proportion of material which \^ould have to be 
added to overcome this defect. In general, it may be stated that the addition 
of the following products tends to overcome the non-weatherproof properties of 
bituminous mixtures: 



Grolp I. 


Group II. 


For Augmenting the Weatherproof Properties 


For Augmenting the Weatherproof Properties 


of Asphaltic Materials Only. 


of Pitches as Well as Asphaltic Materials. 


Asphaltites. 


Animal or vegetable oils and fats. 


Certain native asphalts. 


Wool grease. 


Certain residual oils. 


Fillers (mineral only). 


Blown asphalt. 




Wurtzilite asphalt. 




Certain fatty-acid pitches. 





Of the products included in Group I, the asphaltites, wurtzilite asphalt and 
certain fatty acid pitches (of the saponifiable type) will most effectively improve 
the weather-resisting properties of the mixture, due to the fact that these mate- 
rials of themselves are highly weatherproof. Among the asphaltites, grahamite is 
most weather-resisting, gilsonite and glance pitch ranging next in efficiency and 
being about equal in this respect. Wurtzilite asphalt is extremely weatherproof, 
and the same also applies to the saponifiable varieties of fatty-acid pitch, Only 
certain native asphalts and residual oils are included in this category, for it is 
impossible to lay down any definite rules to differentiate between the non-weather- 
proof and weatherproof varieties, since this can only be determined as the result 
of experience or by an actual exposure test. The physical and chemical tests fail 
to determine definitely whether a native asphalt or residual oil will display the 
optimum weather-resistance in actual service. Certain tests (e.g., large percentages 
of volatile matter and non-mineral constituents insoluble in carbon disulphide), 
may definitely pronounce the material to be non-weatherproof, but if these, by 
chance, prove negative, the court of final appeal is an actual exposure test under 
service conditions. 

Both fluxes enumerated under Group II are equally eflficient from the stand- 
point of weather-resistance, although the first named is superior in its fluxing 
properties. Mineral fillers when added in a finely divided state, or in the form of 
graded particles proportioned to show the minimum percentage of voids (p. 363) 
tend to improve the weather-resistance of all bituminous substances. Those fillers 
which are impermeable to light are most efficient in this respect (p. 393). The 
same rules apply in this connection, as with mineral pigments in linseed oil paints.^ 

Increasing the Tensile Strength of Bituminous Mixtures. For some purposes 
it is important that a bituminous mixture shall have the maximum tensile strength, 

1 " Physical Characteristics of a Paint Coating," by R. S. Perry, Am. Inst, of Architects, Michi- 
gan Chapter, Jun. 4, 1907. 



346 



ASPHALTS AND ALLIED SUBSTANCES 



to enable it to withstand the stresses and strains to which it may be subjected 
in usage. This is of special importance in the case of certain forms of bituminous 
pavements. Two general methods are used for the purpose, viz.: 

(1) Incorporating mineral fillers. 

(2) Increasing the hardness, by blending with harder bituminous substances 
(p. 343). 

The effect of mineral fillers on the physical characteristics is illustrated in the 
following figures, based on the mixtures of a straight-run residual Mexican asphalt 
with 0, 15, 30, 45 and 60 per cent of precipitated calcium carbonate. 



TABLE XXX 



Soft residual asphalt 

Precipitated calcium carbonate 

(Test 9c) Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

(Test 9d) Susceptibility factor 

(Test 106) Ductility at 115° F 

Ductility at 77° F 

Ductility at 32° F 

(Test 11) Tensile strength at 115° F 

Tensile strength at 77° F 

Tensile strength at 32° F 

(Test 15a) Fusing-point (K. and S. method) 
(Test 15b) Fusing-point (B. and R. method) 

Medium residual asphalt 

Precipitated calcium carbonate 

(Test 9c) Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

(Test 9d) Susceptibility factor 

(Test 106) Ductility at 115° F 

Ductility at 77° F 

Ductility at 32° F 

(Test 11) Tensile strength at 115° F 

Tensile strength at 77° F 

Tensile strength at 32° F 

(Test 15a) Fusing-point (K. and S. method) 
(Test 156) Fusing-point (B. and R. method) 



100% 
0% 



0.0 
3.1 

18.4 

19.8 

14 

40 
2.7 
0.0 
0.4 
5.5 

93° F. 
110° F. 



100% 
0% 



85% 
15% 



0.0 
4.6 

22.2 

22.6 

13 

31 
2.6 
0.0 
1.1 
7.5 

98° F. 
115° F. 



85% 
15% 



70% 
30% 



0.0 

6.5 

24.1 

19.5 

10 

13 

0.8 

0.0 

1.7 

9.5 

106° F. 

124° F. 



70% 
30% 



55% 

45% 



3.1 
13.9 
30.4 
14.5 



0.6 
0.5 
0.3 
2.4 
13.0 

163° F. 

188° F. 



55% 

45% 



40% 
60% 



40% 
60% 



2.1 

10.0 

47.3 

38.2 

27 

38 

0.0 

0.0 

1.6 

9.6 

118° F. 

136° F. 



2.7 

12.4 

51.9 

39.7 

22 

13 

0.2 

0.2 

2.2 

14.0 

124° F. 

145° F. 



5.75 

17.65 

54.3 

35.9 

11 

1.1 

0.1 

0.8 

4.3 

20.5 

135° F. 

158° F. 



13. 
26. 
66. 
28. 

0. 

0. 

0. 

1 

6 

27 

190= 

216' 



17.1 
36.6 
80.4 
26.2 



242' 
269' 



* Does not flow when heated. 

It will be noted that the fusing-point, hardness, and tensile strength increase, 
whereas the susceptibility factor and ductility decrease in proportion to the quantity 
of filler added. When the percentage of filler is sufficient to destroy the fluidity of 
the mixture, as in the case of the surface course of sheet asphalt pavements 
(where the filler exceeds 80 per cent by weight), the physical properties of the mix- 
ture depend largely upon the pressure to which the mass has been subjected. 
The greater the compression, the greater will be the hardness, tensile strength and 
density. 

The tensile strength of a soft bituminous mixture increases to a certain point 
upon being blended with harder bituminous substances, but these have a ten- 



METHODS OF BLENDING 347 

dency to reduce the strength, when the mixture reaches the hard and brittle stage 
(see Table XXVI, p. 300). 

Rendering Wax-like, Unctuous to the Feel, or Lessening the Tendency towards 
Stickiness. For certain purposes, it is desirable to impart the foregoing properties 
to bituminous mixtures, especially in manufacturing insulating compounds, rubber 
substitutes, coating compositions for papers, etc. The addition of a small per- 
centage of the following waxes (usually less than 10-15 per cent) will serve to 
accomplish this result: 

Ozokerite. RIontan wax, Pyrogenous waxes. 

These will not amalgamate permanently with bituminous materials, but will 
work their way to the surface in time, forming a thin waxy film which will modify 
the characteristics of the mixture, imparting certain of the physical properties of 
waxes. In the case of ozokerite and pyrogenous waxes only a small percentage 
should be added, otherwise the separation will be sufficiently great to destroy the 
integrity of the mixture. Montan wax may be added in large quantities, as it con- 
stitutes a better flux and shows but a slight tendency towards separation. 

Tertiary and Complex Mixtures. In the case of binary mixtures, the 
characteristics of the blended product may be predicted with a reasonable 
degree of certainty, but with tertiary or quaternary mixtures this is 
extremely difficult, and in many cases impossible to do, even by one 
highly skilled in the art. We must bear in mind that the native asphalts, 
for example, occur in hundreds of varieties, each differing in certain 
respects from the others, or as one authority on the subject aptly expresses 
it: " No two deposits of native asphalt or petroleum on the face of the 
earth are exactly alike." Similarly, blown asphalts, residual asphalts, 
coal-tar pitches, etc., are produced in hundreds of forms, depending upon 
the nature of the crude materials, the temperature to which they have been 
subjected, the length of blowing, the duration of the distillation process, 
and many other factors. These result in the production of a whole series 
of products from any particular raw material, varying in fusibility, hard- 
ness and other physical and chemical characteristics. Since each class 
of raw material is available in hundreds of varieties, it will be apparent 
that the number of possible combinations in tertiary mixtures is infinite. 

In color matching, a given shade may be produced in a dozen different 
ways, each starting with totally different colors, and similarly a given 
bituminous substance may be exactly duplicated in physical characteris- 
tics (i.e., fusing-point, hardness, ductility, tensile strength, volatility, etc.), 
by numerous mixtures, each containing different combinations of different 
materials. 

The only way to match a given bituminous substance is by the '' cut 
and try method." This applies with more force when it comes to tertiary 
and complex mixtures. To exactly duplicate a complex bituminous 



348 ASPHALTS AND ALLIED SUBSTANCES 

mixture is one of the most difficult and at the same time one of the most 
facinating problems in bituminology. At the present stage of the science, 
a chemical analysis of the material to be duplicated will tell nothing. It 
is only an intimate knowledge of the physical properties of the available 
bituminous raw materials, and an inference of their behavior in combina- 
tions, that will assist the expert in synthesizing a mixture having substan- 
tially the same properties as the one to be duplicated. 

The problem is made still more complicated by the fact that although 
we may apparently succeed in duplicating the physical properties of a 
given bituminous mixture, yet there is no way of telling other than from 
an actual service test whether or not it will behave the same on aging or 
upon exposure to the elements. No " accelerated " test is known by which 
this may be accurately predetermined. 

Classes of Bituminous Mixtures. Bituminous substances and their mixtures 
may be roughly divided into three general classes, characterized by being " soft," 
" medium " and " hard " at room temperature. The following table will show 
which of the commercial products belong to the respective classes: 

Soft {liquid) Bituminous Products: 

Dust-laying oils. 

Binders for road surfacings. 

Impregnation for wooden paving blocks, railroad ties, etc. 

Tars and oils for the flotation process. 

Saturating compounds for prepared roofing, flooring, waterproofing, sheathing and insulating 
papers, electrical insulating tape, etc. 

Waterproofing compounds for Portland-cement mortar and concrete. 
Medium (semi-liquid to semi-solid) Bituminous Products: 

Binders for bituminous surfacings, bituminous macadam and bituminous concrete pavements. 

Asphaltic cement for sheet asphalt pavements, asphalt-block pavements and asphalt mastic 
foot-pavements and floors. 

Fillers for wood, brick and stone pavements. 

Bituminous expansion joints. 

Coatings for prepared roofing, flooring, waterproofing, sheathing and insulating papers. 

Adhesive compounds for built-up roofing and waterproofing work; bases of plastic compounds 
for repairing roofs, etc. 

Pipe-dips and pipe-sealing compounds. 

Electrical insulating compounds. 

Rubber substitutes and fillers. 

Moulding compounds. 

Bases of bituminous paints and cements. 
Hard (solid) Bituminous Products: 

Certain forms of electrical insulating compounds. 

Moulding compounds. 

Binders for briquettes. 

Certain forms of pipe dips. 

Bases of varnishes, enamels, japans and certain bituminous paints. 

Processes of Blending Bituminous Substances. The types of apparatus 
for this purpose fall into two groups, viz. : 

(1) Open vessels of semi-cylindrical or rectangular form, as described 



METHODS OF BLENDING 349 

for dehydrating semi-solid and solid native bituminous substances (Chap- 
ter VI). 

(2) Closed horizontal cylindrical vessels provided with an agitator 
in the form of a horizontal shaft carrying short stout blades or paddles 
usually set at an angle. This type is mounted on a masonry foundation 
over a solid or perforated fire-brick arch, and the heating effected by burn- 
ing coal or gas underneath it. The vessel is provided with a manhole 
at the top, through which the bituminous substances are changed, and 
closed with a cap during the melting process to keep out air and prevent 
the vapors from igniting. 

The first type is used where the bituminous substance is heated below 
the flash-point of the constituent flashing at the lowest temperature, and 
the second where it is necessary or desirable to heat the mass above the 
flash-point. Since the mass can safely be heated in the second type to 
higher temperatures and agitated at a greater speed without danger of the 
melted mixture splashing out of the vessel, it follows that with its use the 
prjDcess of amalgamation will take place more, rapidly. 

The dehydrated bituminous substances are introduced into the melting- 
tank, preferably in the melted condition, either by gravity or by means of 
pumps. Where this is not practical, as with high fusing-point products, 
such as the asphaltites or native asphalts containing a large percentage of 
mineral matter, they may be added cold in the solid state, but in this case 
it takes longer to melt up the charge. 

The higher the temperature to which the materials are heated, the 
more rapidly will the combination take place. It is not necessary, or 
in fact desirable to raise the heat to the fusing-point of the ingredients 
melting at the highest temperature, as these will be dissolved by the con- 
stituents fusing at lower temperatures, due to their inherent solvent 
action combined with mechanical agitation. Thus, a grahamite fusing 
at 550 to 575° F. (K. and S. method) will readily combine with mixed- 
base or asphaltic residual oils brought to a temperature of 400° F., par- 
ticularly if the mixture is kept well agitated. The grahamite should be 
introduced in the form of lumps about the size of hickory nuts, in prefer- 
ence to a fine powder, as the latter will sinter together if the charge is not 
agitated, and in addition will make it difficult to tell when the amalgama- 
tion is completed. 

Great care should be taken not to overheat bituminous substances, as they are 
all affected either by a prolonged heating at a moderately high temperature, or 
upon subjecting to a comparatively high temperature for a short time. There are 
no general rules regarding the behavior of bituminous substances under the influ- 
ence of heat. Each will act differently, and resist heat to a greater or lesser degree. 



350 ASPHALT AND ALLIED SUBSTANCES 

It is rarely safe to raise the temperature higher than 450-500° F. in any of the 
manufacturing processes involving the use of bituminous substances.^ Overheating 
will manifest itself by: 

(1) Increasing the specific gravity, viscosity, hardness and consistency, fusing- 
point, flash-point, burning-point, non-mineral matter insoluble in carbon disulphide, 
and carbenes. 

(2) Decreasing the ductility, volatile matter, solubility in carbon disulphide and 
in 88° petroleum naphtha. 

On fluxing native asphalts carrying a substantial percentage of mineral matter, 
it is important to keep the mass well agitated, otherwise the mineral matter will 
settle out and carboniz'^; against the bottom of the tank, retarding the ingress of 
heat, and causing the bottom plates to burn out rapidly. 

When the mixture is to be heated to a high temperature for other than a com- 
paratively short time, it is inadvisable to affect the agitation by means of air, as 
this will increase the fusing-point in the same manner as in the production of 
" blown asphalts " (see p. 287). Mechanical stirrers or dry steam jets are prefer- 
able under these conditions. 

Apparatus for Incorporating Fillers. As fillers are added after the bitu- 
minous mixture has been dehydrated and fluxed to the proper consistency, 
a steam- heated mixing apparatus of small capacity is best adapted for the 
purpose, constructed to mix the charge with great rapidity. Two forms 
of steam-jacketed agitators provided with mechanical mixers are used, 
viz.: 

(1) A rectangular tank with a semi-cyHndrical steam-jacketed bottom, 
commonly provided with two horizontal shafts revolving in opposite 
directions, each carrying two sets of short strong blades or paddles set at 
different angles, to work the bituminous mixture from the ends of the 
vessel towards the centre. The completed mixture is discharged from the 
bottom through a power operated shde-valve (see Fig. 117). 

(2) A vertical vessel of cylindrical form provided with a steam-jacketed 
semi circular bottom, enclosing a vertical shaft carrying blades, geared 
to an auxiliary shaft, offset at one end and provided with smaller blades 
which revolve within the larger ones. The principle of this type is similar 
to that of a common " egg-beater." The inner shell is cast from a single 
piece of metal to avoid danger of leakage. This form of apparatus is 
intended only to mix in such quantities of fillers as will not destroy the 
fluidity of the mixture or prevent it discharging by gravity through a spout 
at the bottom. When fillers are used such as silica, earth-colors, or the 
like, mixtures can be prepared containing 60 to 65 per cent of the mineral 
constituents. 

When it is desired to incorporate light vegetable fillers, such as cork, wood- 
flour, or fibres, a type of mixture may be used similar to the foregoing but mounted 

1 " Effect of Overheating Asphalts," C. J. Frankforter, J. Ind. Eng. Chem., 2, 239, 1910. 



METHODS OF BLENDING 



351 



on trunnions, so that after the mixing is complete, the entire apparatus may be 
tipped bodily, and the contents hoed over the rim while the mass is hot. An 
apparatus of this type is illustrated in Fig. 116. 

Emnlsification. In special cases it is desirable to emulsify liquid to 
semi-liquid bituminous matciials with water. The emnlsification is 
brought about through the intervention of the following classes of sub- 
stances: water-soluble soaps, alkalies, alkaline earths, sodium silicate, 




Courtesy of J. H. Day & Co. 

Fig. 116. — Mixer for Incorporating Large Percentages of Fillers in Asphalt. 



certain mineral oxides, plastic clay, tar distillates including pyridine bases, 
starchy materials, water-soluble gums, Irish moss, sulphonated oils, 
casein, molasses residues, etc. (see p. 354). 

The emulsification is effected cold. If a liquid product is to be obtained, the 
bituminous material and water containing the emulsifying agent are mixed in a 
suitable apparatus provided with a mechanical stirring device. If the product is to 
be produced in paste form, the emulsification is brought about in a "masticator," 
or a " pug-mill " (otherwise known as a " chaser " or " Chilean mill "), in which 
mechanical agitation is coupled with a certain amount of grinding or trituration 
(see p. 459). 



CHAPTER XXIV 

BITUMINOUS PAVING MATERIALS 

Bituminous materials for constructing pavements may be classified 
into the following groups, depending upon the specific purpose for which 
they are to be employed, viz. : 

(1) Bituminous dust-laying oils. 

(2) Bituminous surfacings. . 

(3) Bituminous macadam. 

(4) Bituminous concrete pavements. 

(5) Sheet-asphalt pavements. 

(6) Asphalt-block pavements. 

(7) Asphalt mastic floorings. 

(8) Bituminized wood-block pavements. 

(9) Bituminous fillers for wood, brick and stone-block pavements. 
(10) Bituminous expansion joints. 

These will be discussed in greater detail later.^ 

The bituminous raw materials commonly employed for the above 
purposes embrace the following: 

Crude petroleums. 

Native asphalts. 

Residual oils. 

Residual asphalts. 

Blown petroleum asphalts. 

Asphaltites. 

Refined water-gas tar and water-gas-tar pitch. 

Refined oil-gas tar and oil-gas-tar pitch. 

Refined gas-works coal tar and gas-works coal-tar pitch. 

Refined coke-oven coal tar and coke-oven coal-tar pitch. 

1 " City Roads and Pavements," by W. P. Judson, N. Y., 1907; " Road Preservation and Dust 
Prevention," by W. P. Judson, N. Y. and London, 1908; " The Modern Asphalt Pavement," 
by Clifford Richardson, N. Y., 1908; " Street Pavements and Paving Materials," by Geo. W. 
Tillson, 1st Edition, New York, 1908; " Dust Preventatives and Binders," by Prevost Hubbard, 
1st Edition, N. Y., 1910; " Asphalt Construction for Pavements and Highways," by Clifford Rich- 
ardson, 1st Edition, New York, 1913; " Text Book on Highway Engineering," by A. H. Blanchard 
and H. B. Drowne, 1st Edition, N. Y., 1914; " The Construction of Roads and Pavements," 
by T. R. Agg, 1st Edition, N. Y., 1916. 

352 



BITUMINOUS PAVING MATERIALS 353 

These may be used either singly or in various combinations. In 
special cases distillates are used, including the heavy petroleum distillates 
for manufacturing dust-laying oils, and tar-distillates for impregnating 
wood blocks. 

Bituminous materials are used without other additions in the form of 
bituminous dust-laying oils, fillers for wood, brick or stone pavements 
and in certain forms of expansion joints; and they are used in admixture 
with mineral aggregate for constructing bituminous surfacings, bitu- 
minous macadam, bituminous concrete pavements, sheet asphalt pave- 
ments, asphalt-block pavements, asphalt mastic flooring and certain 
expansion joints. They are also used in combination with wood for 
manufacturing bituminized wood-block pavements; wdth felted fabric 
in forming certain bituminous expansion joints; and in some cases emul- 
sified with water for preparing dust-laying oils, and bituminous cements 
to be used cold. 

Bituminous Dust-laying Oils. Dust-laying oils are also designated 
" dust preventatives " or '' dust palliatives." They are usually liquid 
at room temperature and are adapted for use without heating, on earth, 
graval or macadam roads, for temporarily resisting the formation and 
dispersion of dust under traffic conditions. Dust-laying oils may either 
be used as such, or in an emulsified state with water, and are applied 
to the road, preferably after removing the loose particles of dust, by any 
suitable form of sprinkling or spraying device, as for example an ordinary 
watering cart. 

The function of the dust-laying oil is tw^ofold, namely, to prevent the 
dispersion of dust already formed, and retard the formation of additional 
particles under the attrition of traffic. The saturating, adhesive or binding 
properties of the oil accomplish these results. At best the effect of dust- 
laying oils is temporary, and they must accordingly be renew^ed from time 
to time, usually twice during the first season, and once each year there- 
after, assuming that the traffic conditions are not abnormally severe. 

Bituminous Materials Used. The follow^ing products are employed 
for this purpose: 

(1) Crude petroleums of mixed-basa and asphaltic nature. 

(2) Heavy petroleum distillates. 

(3) Residual oils. 

(4) Cut-back residual asphalts. 

(5) Gas-works coal tar. 

(6) Coke-oven coal tar. 

(7) Cut-back pitches. 

(8) Water-gas tar (rarely). 

(9) Oil-gas tar (rarely). 



854 ASPHALTS AND ALLIED SUBSTANCES 

Bituminous Emulsions. It is sometimes customary to use the prod- 
ucts with water in the form of an emulsion, obtained by mechanical or 
chemical means. Emulsions, on account of their greater fluidity, have 
the advantage of being applied more cheaply than untreated oils or tars, 
thus enabling them to be spread on the road without the use of a special 
form of apparatus. In addition, they are absorbed more rapidly by the 
road surface, and obviate the necessary of interfering with traffic while 
applied, or the annoyance of having the oil tracked about by pedestrians, 
as often proves the case when crude petroleums or tars are used. 

Mechanical emulsions are obtained by mixing the oil (usually crude 
petroleum, heavy petroleum distillates or residual oil) with a suitable quan- 
tity of water, by a mechanical contrivance, just as it is about to be sprayed 
on the road, as for example by means of a rapidly revolving set of blades. 
Oils having a specific gravity approximating that of water will answer best 
for this purpose. 

The following chemical agents have also been used for emulsifying the dust- 
laying oils, viz.: 

(1) Soaps prepared from animal or vegetable oils and fats, which when combined 
with petroleum, residual oils or tars will enable them to become emulsified with 
water. One formula consists in emulsifying the asphalt with oleic acid and am- 
monia,^ another in dissolving 20-25 lb. of common soap in the smallest quantity of 
hot water (40-50 gal.), and then mixing it with 100 gal. of asphalt. Rosin or rosin 
oil soap may also be used.^ 

(2) Alkalies, including ammonia, caustic or carbonated soda or potash, borax, 
slaked lime, etc., will give satisfactory results with tars containing phenolic bodies, 
due to the resulting combination acting as an emulsifier. 

(3) The addition of a small percentage of certain alkaline bases including pyri- 
dine, piccolin or quinolin, will emulsify residual oil, crude petroleum or tar.^ 

(4) Small percentages of colloidal vegetable or animal substances, such as 
saponin, glue, gums, pectin substances, vegetable mucilages,^ sulphite liquors, waste 
molasses liquors ^, starch paste, Irish moss ^ and other glutinous substances dissolved 
in water. The addition of a small proportion of these. substances to the oils or tars 
with or without the addition of soaps, will enable them to emulsify with water. 

(5) A paste made up of colloidal mineral substances, such as metallic oxides, 
silicates, hydroxides, clay,'' sodium silicate ("water glass ")-^ 

lU. S. Pats. 992,313 of May 16, 1911 to L. S. van Westrum; also 998,691 of Jul. 25, 1911 to 
H. R. Kasson and S. S. Saxton. 

2 Ger. Pats. 248,084 of Dec. 5, 1909 and 248,793 of Mar. 17, 1910 to Reinhold Wallbaum; 
U. S. Pats. 1,258,103 of Mar. 5, 1918 and 1,259,223 of Mar. 12, 1918, both to W. M. Fraser. 

3 U. S. Pat. 884,878 of Apr. 14, 1908 to J. P. Van der Ploeg. 

4 U. S. Pat. 834,830 of Oct. 30, 1906 to Karl Mann. 

B " Dust Preventatives and Road Binders," Hubbard, p. 109. 
« U. S. Pat. 943,667 of Dec. 21, 1909 to Carleton Ellis. 

» F. Raschig, J. Soc. Chem. Jnd., 29, 758, 1910; U. S. Pat. 1,240,253 of Sep. 18, 1917, to M. A. 
Popkess. 

8U. S. Pat. 980,513 of Jan. 3, 1911 to Robert Hacking. 



BITUMINOUS PAVING MATERIALS 355, 

(6) Sulphonated vegetable oils such as " turkey red oil."^ 

(7) Soda sludge obtained from oil-refining works (see page 213). 

(8) By means of soluble casein solutions. ^ 

Emulsions are usually marketed under various proprietary names, 
the exact composition being carefully guarded as '' trade secrets," and 
recommended to be mixed with water, in proportions ranging from 10 to 
30 per cent. It is obvious, however, that the smaller the percentage of 
bituminous matter present, the less the efficiency of the emulsion as a 
dust-laying medium, and the more often it must be renewed. The use 
of emulsions is attendant with the following disadvantages: They are 
usually applied in such weak solutions that their efficiency is impaired; 
the water present in the emulsion has no value from the view-point of 
dust-laying and necessitates the purchaser paying freight on this inactive 
ingredient; and further, emulsions prepared from residual oils derived from 
non-asphaltic and mixed-base petroleums are very apt to wash off the road 
upon being subjected to the action of rain or snow combined with the 
mechanical grinding under the wheels of traffic. 

Non-emulsified Products. Non-emulsified oils and tars are usually 
less expensive in the long run. They are generally applied cold, but in 
certain cases, and particularly during cold weather, better results may be 
obtained by sprinkling them on the road in a heated state. The best 
practice necessitates using from ^ to i gal. per square yard, depending upon 
the nature of the road, the quantity of dust in situ, and whether or not the 
road has been oiled previously. On a road oiled at regular intervals, 
0.1 to 0.2 gal. per square yard is sufficient after the initial application. 
The surface should then be sprinkled lightly with sand, using a cubic 
yard for every 75 to 125 sq. yd. of surface, to prevent the oil being tracked 
about by pedestrians and vehicles. A longer period should be given 
the oil to soak into gravel or macadam roads since they are denser and 
less porous than dirt roads. For the same reason, the oil must be applied 
with great care to provide a uniform distribution, and to prevent it 
accumulating in " pools." 

Non-asphaltic petroleums and their residual oils are not looked upon 
with favor, owing to their deficiency in ^' binding " properties. Mixed- 
base petroleums and their residual oils give better results, but they are not 
regarded as equal to the asphaltic petroleums and their residual oils. In 
general residual oils give better results than crude petroleums, since they 
are more '' concentrated." It is still an undecided matter whether, other 

1 U. S. Pats. 931,520 of Aug, 17, 1909 to Juliua Stockhausen; 998,691 of Jul. 25, 1911 to H. R. 
Kasson and S. S. Saxton. 

»Ger. Pat. 240,482 ol May 1, 1910 to Aktiengesellsch&ft fUr Aaphaltierung und Dachbedekun^. 



356 ASPHALTS AND ALLIED SUBSTANCES 

things being equal, petroleum products or " tars " are preferable, and much 
may be said on both sides of the question. Cut-back residual asphalts 
and cut-back pitches have also been largely used. They have many 
advantages, and among others, the fact that they set up rapidly when 
applied to the road, and the residue is apt to have better " binding " prop- 
erties than would be the case if the corresponding crude or straight dis- 
tilled products were used. 

General Considerations. The following precautions should be followed to get the 
best results: 

1. All the loose dust should be removed from the road before applying the dust- 
laying oil. 

2. The road should be thoroughly dry and the oil applied preferably on a warm 
sunny day, or if this is not possible, the oil should be heated slightly before it is 
spread. 

3. The oil should be allowed to soak into the road thoroughly before reopening 
it to traffic. 

4. The oil should not be too viscous, otherwise it will fail to penetrate prop- 
erly. Best results are obtained with oils having a specific viscosity (on the the 
first 50 c.c.) when tested with the Engler viscosimeter (Test 8a) at 77° F. as follov/s: 

(a) Petroleum products for use as dust palliatives (i.e., three to four applications 
per year at intervals), less than 10. 

(6) Petroleum products for use as road oils to be applied cold (i.e., two appli- 
cations per year, intended to build up a bituminous surface), 80-120. 

(c) Refined tars for use as dust palliatives, 8-13. 

(d) Refined tars for use as road oils to be applied cold, 25-35. 

(e) Refined tars for cold patching, 40-70. 

5. If the oil contains an excess of volatile matter, too much will eventually be 
dissipated through evaporation to enable the residue to fulfil its function efficiently. 
The volatile matter at 325° F. in 5 hours should not exceed 30 per cent in the case of 
petroleum products, nor must the residue appear " greasy." The greater its adhe- 
sive qualities and tensile strength (" cementitiousness ") at 77° F. (Test 11), the 
more efficiently will the original oil bind together the dust particles. Tar products 
on distillation (Test 20) should yield the following percentages of distillate: 

(a) Refined tars for use as dust palliatives: to 170° C. less than 5 per cent; 
to 270° C. less than 30 per cent; to 300° C. less than 40 per cent. 

(6) Refined tars for use as road oils to be applied cold: to 170° C. less than 2 
per cent; to 270° C. less than 25 per cent; to 300° C. less than 35 per cent. 

(c) Refined tars for cold patching: to 170° C. more than 2 per cent; to 270° C. 
15-25 per cent; to 300° C. less than 3G per cent. 

6. Petroleum products should show not exceeding 1 per cent non-mineral 
matter insoluble in carbon disulphide; refined tars for use as dust palliatives or as 
road oils to be applied cold, not more than 10 per cent free carbon (Test 31); and 
refined tars for cold patching, not exceeding 20 per cent free carbon. 

7. The dust-laying oil should not show a tendency to emulsify when subjected 
continuously to the action of moisture or upon being ground up in the form of a 
paste with the dust or mud generated by traffic. Certain oils and especially those 
prepared from non-asphaltic or mixed-base petroleums are apt to become miscible 



BITUMINOUS PAVING MATERIALS 357 

with water under these conditions, and wash away from the surface of the road. 
The product may be tested for this defect by grinding the residue remaining after 
the volatihty test in a mortar with an equal weight of colloidal clay made into a 
paste with water, and obse^-ving whether any emulsification takes place. 

Bituminous Surfacings. A bituminous surfacing consists of a layer 
of appreciable thickness constructed on top of a newly prepared or an old 
roadway, by the application of one or more coats of bituminous material 
interposed with gravel, sand or stone chips. When used for surfacing 
gravel, stone or concrete roads, it is usually termed a " carpet " or a 
" carpeting coat," and when used for surfacing roads constructed of a 
bituminous wearing course including bituminous macadam and bitu- 
minous concrete pavements, it is referred to as sl " seal-coat." In the 
latter case the function of the bituminous surfacing is to fill the voids of 
the bituminous foundation and produce a smooth and uniform wearing 
surface. 

The objects of the bituminous surfacing are to prevent the formation 
of dust by attrition, to provide a somewhat elastic cushion or '' carpet " 
to take the wear and preserve the denser material upon which it is laid, 
to make the road less noisy, and to increase the comfort of those w^ho travel 
over the pavement. Bituminous surfacings will only give good results 
on roads providing a firm and well compacted foundation. New roads 
should accordingly be opened up to traffic for some time until all the 
small particles and loose dust have been w^orn off, and any local settling 
may have taken place. 

Bituminous Binder. Bituminous binders for use in constructing 
bituminous surfacings may be divided into two groups, viz.: (a) suit- 
able for application to gravel, stone or concrete pavements, and for the 
maintenance of bituminous macadam and bituminous concrete pave- 
ments; (h) suitable for preparing the original bituminous surfacing in 
constructing bituminous macadam and bituminous concrete pavements 
(usually termed " seal coats "). The first group only will be considered 
under this heading. The bituminous binders included in the second 
group will be described under the headings of bituminous macadam and 
bituminous concrete pavements, as they consist of the same character 
of bituminous materials as used in the construction of the wearing course 
of these respective pavements 

The bituminous materials used for preparing the bituminous surfacings of group (a) 
are usually viscous, semi-liquid to semi-solid in consistency and suitable for appli- 
cation in a heated condition by a mechanical distributor capable of forcing it on 
the road under more or less pressure. They are usually applied at a temperature 
of 225-275° F., and should possess or develop shortly after their application . suffi- 



358 



ASPHALTS AND ALLIED SUBSTANCES 



cient adhesiveness to bind together the covering of sand, gravel or stone chips. 
The bituminous material is frequently composed of a " cut-back " residual asphalt 
or pitch, prepared from a base of great adhesiveness, combined with a suitable 
proportion of volatile constituents intended to evaporate within a short time after 
the bituminous surfacing is applied. The following may be used for preparing the 
surfacing: 

(1) Fluxed native asphalts. (It is possible to use these, but at present none are 
so employed.) 

(2) Blown petroleum asphalt of the proper consistency. 

(3) Residual asphalts, including " cut-back " products. 

(4) Residual or refined tars, including water-gas tar, oil-gas tar, gas-works coal- 
tar and coke-over tar. 

(5) Cut-back pitches, including cut-back water-gas-tar pitch, oil-gas-tar pitch, 
gas-works coal-tar pitch, and coke-oven coal-tar pitch. 

The bituminous binder should comply with the following characteristics when 
tested in its pure state: 



Visooaity by float test at 90° F. (Test 8d) 

Ductility at 77" F. (Tests lOo and 106) 

Fusing-point (K. and S. method, Test 15a) 

Volatile at 325° F. in five hours (Test 16o) 

Viscosity residue by float test at 122° F, (Test 8d) 
Distillation test (Test 20): 

To 170° C. (by weight) 

To 270" C. (by weight) 

To 300" C. (by weight) 

Soluble in carbon disulphide (Test 21a) 

Non-mineral matter insoluble (Test 216) 

Mineral matter (Test 21c) 

Soluble in 88" naphtha (Test 23) 



Tar 


Asphaltic 


Products. 


Products. 


60-150 


60-150 


>50 


>50 


<105° F. 


<105° F. 




<15% 




>110 


<1% 




<15% 




<25% 




>85% 


>98% 


<15% 


<J% 


<Wo 


<1% 




>90% 



Mineral Aggregate. The top dressing should consist of coarse sand, 
fine gravel or screened grit (stone chips) whose particles vary from | to 
I in. in their longest dimension. The grit may be graded from f in. down, 
but should contain no " dust." One cubic yard of sand weighing approxi- 
mately 2700 lb. should cover 50 to 100 sq. yd. of road surface in the hot 
process and 100 to 150 sq.yd. in the cold treatment (i.e., dust-laying oils). 
The harder the character of the top dressing, the better. Cubical particles 
are less liable to displacement under traffic than rounded particles. 

Preparing and Applying the Surfacing. The following steps should be 
carefully observed: _ 

(1) The original cross-section of the road should be restored, proper 
drainage provided, and any ruts or depressions filled with crushed stone 
or gravel, levelled by rolling, and thoroughly bonded. 

(2) Any loose dust, chips or other particles should be removed by 



BITUMINOUS PAVING MATERIALS 359 

sweeping with hand or power brooms, or in extreme cases with shovels 
or power scrapers. 

(3) The weather should preferably be clear and warm. 

(4) The road sm'face should be clean and dry. This is essential to 
secure the proper bonding of the surfacing to the wearing course. In 
certain cases a light preliminary cold application of liquid bituminous 
material or '^ primer " will promote the adhesion. With macadam, 
best results are obtained by removing the fine particles between the larger 
stones to a depth of f to ^ in. to enable the surfacing to " key " with it. 

(5) The tar or asphalt should be heated to 225 to 275° F., and applied 
with a suitable pressure distributor, which w411 impinge it against the 
surface of the road in jets propelled at great velocity, and at the same time 
remove any dust which may have been overlooked. If the pressure is 
too great, the bituminous material is likely to be atomized into fine particles 
whose iiTipact will be lessened. 

(6) The quantity of bituminous material required for the first treat- 
ment will vary from i to J gal. per square yard of surface, averaging 
i gal., depending upon the character and smoothness of the surface. 
It should be applied uniformly and smoothly. 

(7) Some recommend that the bituminous surfacing should be allowed 
to remain on the road at least twelve hours, to enable it to soak in as much 
as possible before the mineral surfacing is applied. Others recommend 
placing the top dressing immediately. 

(8) After the top dressing is applied, it should be thoroughly rolled 
with a steam roller to incorporate the mineral matter with the bituminous 
coating. 

(9) The finished bituminous surfacing should vary in thickness from 



General Considerations. The success of this method will depend upon: 

(1) The nature of the foundation to which the bituminous surfacing is applied. 
Macadam, concrete and well-constructed bituminous-macadam pavements give the 
best results. Bituminous surfacings do not stand up as well on gravel roads, as they 
are apt to peel off after a time, unless a primer is used, 

(2) The thoroughness with which the bituminous surfacing adheres to the foun- 
dation. 

(3) The nature of the binder used. Bituminous substances whose residues 
possess great ductility, tensile strength and " adhesive " qualities will give the best 
results. They should not be too susceptible to temperature changes or contain too 
large a percentage of volatile constituents. Petroleum products made from asphaltic 
petroleum will give better results than those obtained from a mixed-base petroleum. 

(4) The nature of the top dressing. Cubical particles of grit or stone-chip- 
pings free from dust, produced from hard rocks will give better results than min- 
eral matter derived from soft rocks, which are liable to powder under heavy traflfic. 



360 ASPHALTS AND ALLIED SUBSTANCES 

Rounded mineral particles are not as satisfactory as angular ones, as they are more 
apt to become displaced. 

Numerous mechanical appliances have been devised for spreading the bitu- 
minous material, the modern and most efficient ones being operated by a motor 
which serves not only to propel the vehicle, but also to apply the bituminous 
material imder pressure. Heat is supplied by burning wood or coal in a small grate 
underneath the tank. Steam-jacketed tanks are also used. 

Bituminous Macadam. This form of pavement is also known as 
" asphalt macadam," " bituminous gravel," " bituminous broken stone," 
" asphalt broken stone," etc. Its wearing course is composed of mineral 
particles bound together and having the interstices filled with a bituminous 
binder introduced by the " penetration method," which consists in first 
rolling the mineral particles in place and applying the melted bituminous 
binder afterwards. 

Foundation Course. The firmer the foundation, the more durable will 
the pavement be. Either a Telford macadam, or well drained gravel 
foundation is recommended. Sand or gravel roads are frequently too 
soft to give good results. If the foundation is worn or rutted or filled with 
holes, it should be levelled and rolled before the surface course is applied. 

Mineral Aggregate. Upon the foundation course is spread an inter- 
mediate course composed of J- to 3- in. broken stone, which after rolling 
is compacted in a layer 2 in. deep on old macadam roadways or 5 in. deep 
on new roadways designed to carry heavy traffic. This is bonded together 
by filling the interstices with smaller-sized stone, sand, screenings or 
stone-dust, and rolled until thoroughly compacted. Upon the inter- 
mediate course is spread the surface course which is subsequently treated 
with the bituminous binder. When the surface course is to be applied in an 
uncompacted layer 4 in. thick, corresponding to 3 in. after rolling, the 
stone particles may vary from 2 to 3J in. When the surface course is to 
be applied in an uncompacted layer 3 in. thick corresponding to 2 in. 
after rolling, the stone particles may range from 1 to 2 J in. All depres- 
sions must be filled. Crusher stone consisting of cubical fragments gives 
the best results. Crushed gravel may be used for the mineral aggregate 
in locahties where broken stone is not obtainable. 

Bituminous Binder. The binder used in penetration method may con- 
sist of the following groups of products: 

(1) Native asphalts used alone when of a suitable consistency, or else fluxed to 
grade with softer native asphalts, residual oil, soft residual asphalts or soft blown 
petroleum asphalt. 

(2) Asphaltites fluxed to the required consistency and fusing-point with residual 
oil, soft native asphalt, soft residual asphalt, or soft blown petroleum asphalt. 

(3) Residual asphalts used alone when of the required consistency, or else fluxed 



BITUMINOUS PAVING MATERIALS 



361 



to grade with residual oil, soft native asphalt, soft residual asphalt or soft blown 
petroleum asphalt. 

(4) Blown petroleum asphalts used alone when of the proper consistency, or 
else fluxed to grade with soft native asphalts, residual oils or soft residual asphalts. 

(5) Water-gas-tar pitch, oil-gas-tar pitch, gas-works coal-tar pitch or coke-oven- 
tar pitch, used either singly or in various combinations, and without other additions 
when of the required consistency; or else if too hard, cut back to grade with the 
corresponding liquid tar evaporated to remove the highly volatile oils, or a small 
proportion of high boiling-point distillate derived therefrom. 

The bituminous binder should comply with the following tests: 



Viscosity by float test at 122° F. (.Test 8c?) 

Penetration at 77° F. (Test 96) 

Penetration at 32° F. (Test 9b) 

Ductility at 77° F. (Test 10a or 106) 

Fusing-point (B. and R. method, Test 156) , 

Fusing-point (Cube method, Test 15c) 

Volatile at 325° F. in five hours (Test 16a) 
Penetration residue at 77° F. (Test 96) 

Flash-point (Test 17a) 

Distillation test (Test 20): 

To 170° C. (by weight) 

To 270° C. (by weight) 

To 300° C. (by weight) 

Fusing-point residue (Test 15c) 

Soluble in carbon disulphide (Test 21a).. . . 
Non-mineral matter insoluble (Test 216) . . . . 

Mineral matter (Test 21c) 

Carbenes (Test 22) 

Soluble in 88° naphtha (Test 23) 



Tar 
Products. 


Asphaltic 
Products. 


90-120 




80-160 




>8 


>25 


>25 
95-135° F 


85-115° F. 




<5% 
> ^ original 
penetration 
> 350° F. 




>325° F. 

<1% 

<io% 

<20% 
<150° F. 

>85% 
<15% 

<^% 








>97% 

<2% 

<1% 

65-85% 





Preparirig and Applying the Surface Course. The surface course is 
applied to the intermediate course as described, in a layer 2 to 3 in. thick 
when compacted, and sprinkled with bituminous binder under a pres- 
sure of 30 to 60 lb. per square inch from a mechanical contrivance similar 
to that used in the surfacing method. Very soft rock should be sprinkled 
before rolling. The bituminous material may be heated between 250 and 
300° F. in the case of tar products, and from 300 to 350° F. with asphaltic 
mixtures, and applied at the rate of J gal. per square yard for each inch 
thickness of the compacted wearing surface. The road is then imme- 
diately covered with a dusting of | in. screenings preferably heated, and 
well rolled with a 15 to 18-ton roller, after which a seal- coat of bituminous 
material (p. 367) is applied, at the rate of J to | gal. per square yard, 
covered with chips and again rolled. 



362 ASPHALTS AND ALLIED SUBSTANCES 

General Considerations. The following precautions should be observed: 

(1) The foundation course should be unyielding and substantial. 

(2) Tough and durable stone of cubical form and free from dust should be 
used as mineral aggregate in the wearing course. 

(3) The bituminous binder should be distributed uniformly throughout the entire 
wearing course. This may be assured by applying the binder in two or more layers 
on relatively thin courses of aggregate. 

(4) The bituminous binder should be applied in just the right quantity, neither 
too much nor too little. If too much is applied, the binder will " bleed " from the 
road in warm weather, and if too little, the bond will be broken in service. 

Bituminous Concrete Pavements. This method differs from the fore- 
going in the fact that the mineral aggregate is heated and mixed with the 
bituminous binder before it is applied to the road. This overcomes the 
main difficulty of the penetration method and insures a uniform distribu- 
tion of the bituminous material. The name '' bituminous concrete " 
is given on account of its analogy to a Portland-cement concrete, in which 
the mineral aggregate has its voids filled with Portland cement in one case 
and with a bituminous cement in the other. It has also been termed 
'' stone-filled sheet asphalt pavement," and may be regarded as a mortar 
of the composition used in the construction of the surface course of sheet 
asphalt pavements, having J to IJ in. stone uniformly distributed and 
embedded therein. This type of construction is rapidly superseding 
bituminous macadam, in spite of the fact that the latter is considerably 
less expensive. The modern tendency is to produce a very dense wearing 
course, characterized by a smaller proportion of voids than in bituminous 
macadam. 

Foundation or Base Course. The most satisfactory foundation con- 
sists of a Portland-cement concrete, or a well-compacted macadam; less 
satisfactory results being obtained from gravel or broken stone founda- 
tions. The same precautions should be followed in levelling and grading 
the macadam, broken stone or gravel foundation as described under the 
respective headings '' Bituminous Surfacings " and '^ Bituminous Mac- 
adam." In the case of a Portland-cement concrete foundation, the direc- 
tions should be observed as described on p. 367. Macadam foundations 
should never be less than 6 in. thick, or Portland-cement concrete less than 
4 in. 

Mineral Aggregate. This should be selected and proportioned with the 
greatest care, since the success or failure of the pavement wiU largely 
depend upon the character and blending of the aggregate. It may con- 
sist of a screened rock of the sizes used for the penetration method, or an 
attempt may be made to reduce the percentage of voids by using a graded 
aggregate consisting of crusher-run stone, or a mixture of crusher-run 



BITUMINOUS PAVING MATERIALS 363 

stone with sand, with or without the addition of dust or filler. When such 
aggregate is not available, sand passing a J-in. screen and gravel ranging 
in size from J to IJ in. may be used in such proportions that the mixture 
will have the smallest percentage of voids (determined as described on 
p. 369). The stone should be hard and tough with cubical fragments. 
Crushed quartz or trap-rock are recommended, but hard, finely crystalline 
limestone will also give good results. Granite is less satisfactory, and 
gravel should only be used where the other types of stone are not procur- 
able. Slag, shells or cinders are not recommended. In the western portion 
of the United States, where hard rocks are not available for aggregate, 
bituminous concrete pavements have not given very satisfactory results. 

The sand should be clean, graded and composed of medium sharp grains, neither 
too angular nor rounded. Sands are classified as beach, river, bank, disintegrated 
sandstone and artificial sands, but each group varies in its characteristics, so that it 
is impossible to reach any conclusions regarding their relative efficiencies without 
subjecting them to a granularmetric examination. 

Sometimes the sands carry sufficient fine particles to satisfactorily fill the voids. 
When this is not the case, additional dust or filler should be added, consisting of 
ground limestone, trap-rock, volcanic rock, silica, shale, powdered clay or marl and 
either Portland or natural cement. At the present time limestone dust is most 
commonly used for this purpose and sometimes Portland cement. Fillers should be 
of such a texture that at least 75 per cent will pass a 200-mesh sieve, and not less 
than 66 per cent remain suspended in water at 68° F. for fifteen seconds (see 
Elutriation Test, p. 541.) The amount of filler added will depend upon: 

(1) Whether the bituminous cement contains mineral matter. 

(2) Whether there are any fine particles of " dust " present in the sand. 

The grading of the stone, sand and filler should be controlled very carefully to 
obtain an aggregate of the greatest possible density, or in other words, the smallest 
percentage of voids. Thus, the voids of the broken stone should be completely 
filled with sand, the voids of the sand in turn filled with dust, and the voids of 
the dust in turn filled with bituminous cement. The " voids " may be determined 
by finding the specific gravity of the stone, sand and dust respectively^, and then 
calculating the proportion of voids in a given volume. This may be arrived at by 
finding the weight of a given volume moderately compacted. The voids will then 
be found by dividing the weight by the gravity, and subtracting the result from the 
volume. The voids are figured in percentage. 

Another method consists in filling a receptacle of exactly 1 cu. ft. capacity with 
the aggregate moderately compacted. A measured volume of water is poured into 
the receptacle until it is ready to overflow, the exact volume of water used being 
equal to the volume of voids in the aggregate or filler under test. The propor- 
tion of bituminous binder to be added should be calculated from the volume of 
voids in the completed mineral aggregate. In most cases the proportion of bitu- 
minous cement is expressed in percentage by weight of the final mixture containing 
the aggregate. This, however, is liable to give misleading results, as correctly pointed 
out by Hubbard, ^ who suggests that the specific gravity of both the aggregate and the 

" The Bitumen Content of Coarse Bituminous Aggregates," Proc. Int. Assoc. Testing Materials, 
6th Congress, 11, XXV-2. 1912. 



364 



ASPHALTS AND ALLIED SUBSTANCES 



pure extracted bituminous cement should be reported. To show the fallacy of the 
method of expressing the proportion of bituminous cement by weight, Hubbard 
assumed the case of two aggregates both having the same percentage (6 per cent) 
by weight of bituminous cement free from mineral matter, the aggregate in one case 
having a specific gravity 2.50 and the pure bituminous cement L17, and in the 
other case the aggregate 3.50 and the pure bituminous cement 0.96. The per- 
centage of bituminous cement by volume will, however, vary greatly as shown by the 
following figures: 



Per Cent 
by Weight. 



Specific 
Gravity. 



Proportion 
by Volume. 



Per Cent 
by Volume. 



First mixture: 

Aggregate 

Pure bituminous cement 

Total 

Second mixture: 

Aggregate 

Pure bituminous cement 

Total 



94 



100 



94 



100 



2.50 
1.17 



3.50 
0.96 



37.6 
5.1 



26.9 
6.3 



100 



100 



It will be observed that although both mixtures contain the same percentage 
of bituminous cement by weight, they show a variation of 7 per cent in their per- 
centages expressed by volume, which is more than sufficient to result in the success 
or failure of the paving mixture. The following figures show the relation of the 
percentages by volume and weight of a dense mixture used for heavy traffic (River- 
side Drive, New York City).^ 





Per Cent 
by Weight. 


Per Cent 
by Volume. 


Pure asphalt (Bermudez) 

Portland cement 

vSand 


9.82 
10.25 
26.64 
53.29 


22.48 

8.03 

24.39 

45.10 


Stone 

Total 


100.00 


100.00 



Specific gravity at 77° F. when ultimately compressed: 2.434 

In arriving at the proper proportions, neither the dust nor the bituminous 
cement should be present in excess, as these tend to make the mixture too smooth 
to form a proper bond with the foundation, also too slippery under traffic. 

Bituminous concrete pavements may be sub-divided into two classes, viz.: 

(1) Containing less than 10 per cent of stone passing a ^-in. screen and having 
greater than 21 per cent of voids, based on the so-called " Topeka specification " ; and 

(2) Containing greater than 10 per cent of stone passing a ^-in. screen and 
having less than 21 per cent of voids in the mineral aggregate, based on the " bitu- 
lithic specification." 2 Typical mixtures are included in the following table: 

J Private communication from Clifford Richardson. 
^Embodied in U. S. Pats. 675,430 of Jun. 4, 1901; 727,505 and 727,512 ui May 5, 1903; 
738,965 of Sep. 15, 1903; all issued to F. J. Warren. 



BITUMINOUS PAVING MATERIALS 



365 





Topeka 
I\Iix- 






Richard- 


Bitu- 




Richard- 


Wash- 




Used in 


Used in 


son's 


lithic 


Warren- 


son's 


ington, 




ture. 


N. Y. 


Spokane. 


Mix- 
ture. 


Mix- 
ture. 


ite. 


Mix- 
ture. 


D. C. 
1911-14 


Passing 200-mesh sieve . 


5-11 


11.9 


4-8 


8.7 


4-7 


5-10 


2-10 




Passing 100-mesh sieve. 






5-10 


8.6 








3-10 


Passing 80-mesh sieve. . 




14.5 


10-20 


8.7 




15-20 




\-2 


Passing 40-inesh sieve.. 


18-30 


18.6 


15-30 


23.2 








3-6 


Passing 10-mesh sieve.. 


25-55 


18.9 


25-40 


10.6 


24-32 


5-10 


25-35 


15-30 


Passing 8-mesh sieve. . . 














1-3 


^-3 


Passing i in. screen.. . . 


8-22 


19.1 


15-40 


22.0 


8-12 


5-10 


3-12 


3-20 


Passing 5 in. screen.. . . 


<10 


8.1 


<10 


10.0 


12-20 


10-20 


10-30 


15-25 


Passing 1 in. screen. . . 










26-35 \ 


40-60 


/ 20-35 


15-30 


Retained on 1 in. screen. 










36-50 i 


I 0-10 


0-20 


Bituminous cement 


7-11% 


8.9% 


7-10% 


8.2% 


7-9^% 


5-10% 


7-9% 


7-8% 


Voids in aggregate .... 


>21% 




>21% 


>21% 


<21% 


<21% 


15-20% 


20-21% 



Percentages expressed by weight. 

Bituminous Cement or Binder. The bituminous cement is semi- 
solid in consistency, and may be composed of the groups of bituminous 
materials enumerated under '^ Bituminous Macadam " (p. 360). It 
should comply with the following characteristics: 



Viscosity by float test at 122° F. (Test 8d).. 

Penetration at 115° F. (Test 96) 

Penetration at 77° F. (Test 9b) 

Penetration at 32° F. (Test 96) 

Ductility at 77° F. (Dow Method, Test 10a) 

Tensile strength at 77° F. (Test 11) 

Fusing-point (K. and S. method, Test 15a).. 
Fusing-point (B. and R. method, Test 156) . 

Fusing-point (Cube method. Test 15c) 

Volatile at 325° F. in five hours (Test 16a).. 

Penetration residue at 77° F. (Test 96) 

Volatile at 500° F. in four hours (Test 16a) . 

Flash-point (Test 17a) 

Distillation test (Test 20): 

To 170° C. (by weight) 

To 270° C. (by weight) 

To 300° C. (by weight) 

Fusing-point residue (Test 15c) 



Soluble in carbon disulphide (Test 21a)., 
Non-mineral matter insoluble (Test 216) 
Mineral matter (Test 21c) 



Carbenes (Test 22) 

Non-mineral matter soluble in 
(Test 23) 



naphtha 



Tar Products. 



120-180 



>10 
>0.5 



115-150° F. 



>350° F. 

<1% 
<10% 
<20% 
<175° F. 

>80% 

15-25% 

<h7c 



Asphaltic Products. 



<350 

60-120 

>25 

>10 

>0.5 

80-110° F. 

100-135° F. 



<3% 
> \ original penetration 
<7% 
>400° F. 



/ > 65% for Trinidad binder 
I > 95% for other binders 

<2^% 
f <30% for Trinidad binder 
^ <35% for other binders 

<2% 



>75% 



366 ASPHALTS AND ALLIED SUBSTANCES 

The important features of the bituminous cement are as follows: 

(1) Its penetration (Test 96) should be controlled within definitely prescribed 
limits. 

(2) It should be slightly susceptible to temperature changes (Test 9d). 

(3) It should possess great ductility (Test 10a). 

(4) It should have great tensile strength (Test 11). 

(5) It should show but a small percentage of volatile matter (Test 16). 

(6) Asphaltic cements should contain only small percentages of non-mineral 
matter insoluble in carbon disulphide (Test 21a), also carbenes (Test 22). 

Good results have been obtained by utihzing the surfacing material ripped from 
old sheet asphalt pavements (p. 368), mixed with a suitable proportion of coarse 
stone, and enriched with additional bituminous cement, softer than that originally 
employed in the sheet asphalt surfacing mixture,^ since the bituminous cement of 
bituminous concrete pavements should be considerably softer than that used in the 
wearing course of sheet asphalt pavements. The following figures show the rela- 
tive penetrations at 77° F. (needle pentrometer Test 96): 

Wearing surface of sheet asphalt pavements .Average of 35 

Bituminous cement in bituminous concrete pavements Average of 85 

Bituminous binder in bituminous macadam pavements Average of 120 

The greater the percentage of filler in the aggregate, the softer the bituminous 
cement may be, and the larger its proportion incorporated in the mixture (see 
Sheet Asphalt Pavements, p. 369). 

Preparing and Applying the Mixture. The best practice provides that 
the stone and sand (or filler) shall be heated separately in a rotary heater, 
as the particles of sand due to their smaller size will heat more rapidly. 
With tar products, the aggregate should be heated not exceeding 300° F., 
and with asphaltic products not exceeding 400° F. The coarse and 
fine portions of the heated aggregate respectively are stored in separate 
bins so that may be weighed individually.^ The bituminous cement 
should also be melted separately to a temperature corresponding to that 
of the aggregate, whereupon suitable proportions of the stone, sand, 
filler and bituminous cement are mixed together in a twin-pug or other 
suitable mixer (see p. 372) for at least one minute at a temperature of 
275 to 375° F. When thoroughly mixed, the bituminous concrete, now 
at a temperature of 250 to 325° F., is hauled to the road in covered wagons, 
and spread on the street at 230 to 280° F. with heated rakes or shovels 
forming a uniform layer of the desired thickness. The mixture is there- 
upon compressed by an 8 to 10-ton roller into a uniform layer either 2 
or 3 in. thick, depending upon the severity of the traffic encountered. 
Another alternative, representing what is now considered to be very good 
practice, consists in first applying 2 in. of close binder (see Sheet Asphalt 
Pavement, p. 368), which in turn is surfaced with 1 to IJ in. of bituminous 

1 U. S. Pat. 938,698 of Nov. 2, 1909 to J. A. W. Pine. 

2 Clifford Richardson, Eng. News, 80, 109, 1908. 



BITUMINOUS PAVING MATERIALS 367 

concrete (asphaltic). The road may be finished in this manner, or it 
may be finished by applying a seal coat. If without the seal coat, a light 
dusting of powdered limestone or Portland cement should be spread on 
the surface and rolled in. 

Finishing Coarse Aggregates with a Seal Coat. To obtain the best 
results with coarse aggregates a seal coat should be applied under pres- 
sure at 200 to 350° F., and manipulated in substantially the same manner 
as described for bituminous surfacings {" carpet coats "), using J to 1 
gal. per square yard, covered with pea gravel or stone chips (the particles 
measuring J to | in. in diameter) at the rate of 1 cu.yd. per 50 to 100 
sq.yd., and firmly rolled in place. In some cases the seal coat consists 
of the same bituminous cement used for preparing the bituminous con- 
crete, and in other instances a harder bituminous cement, testing as follows: 

(Test Qb) Penetration at 115° F Less than 100 

Penetration at 77° F 60-30 

Penetration at 32° F Greater than 10 

(Test loa) Fusing-point (K. and S. method) 110-115° F. 

(Test 156) Fusing-point (B. and R. method) 130-140° F. 

(Test 15c) Fusing-point (Cube method) 175-200° F. 

(Test 16o) Volatile at 325° F. in five hours Less than 1% 

Penetration residue at 77° F Greater than 25 

Penetration residue at 32° F Greater than 10 

Volatile at 500° F. in four hours Less than 3% 

(Test 17o) Flash-point Greater than 400° F. 

(Test 10a) Ductility at 77° F. (Dow method) Greater than 2 

The remaining tests in either case should be the same as for the cement in the 
bituminous concrete la3'er. 

General Considerations. When properly constructed, bituminous concrete is 
as durable as any form of bituminous pavement, but its cost is high. It has the 
advantage over the sheet asphalt pavement in being less slippery in wet or freezing 
weather, due to the grit embedded in the surface. Failures are due to an unstable 
foundation, the improper proportioning of the aggregate, or the use of a bituminous 
cement of faulty characteristics. 

Sheet-asphalt Pavements. A sheet-asphalt pavement is one pre- 
pared by the mixing method, composed of an intermediate or binder course 
of bituminous concrete, and a wearing course composed of asphaltic 
cement and sand of predetermined grading, with or without the addition 
of mineral filler (dust). 

Foundation or Base Course. The foundation or base course may 
consist of a brick or a block pavement, and sometimes old macadam. 
The most satisfactory foundation is composed of Portland-cement concrete 
4 to 9 in. thick, depending upon the severity of traffic. The concrete 
should consist of Portland cement, gravel or broken stone, and sand in 
proportions ranging from 1 : 2 : 5 to 1 : 3 : 6, depending upon the nature 
of the aggregate available. The surface of the hydraulic concrete should 



368 ASPHALTS AND ALLIED SUBSTANCES 

be levelled carefully and finished smooth, since any irregularities will be 
transmitted to the wearing course, giving it an uneven surface. 

Intermediate or Binder Course. This may be classified in two types 
known as " open binder " and " close binder " respectively. The former 
corresponds to the ungraded coarse-aggregate bituminous concrete, and 
the latter to a graded bituminous concrete. Asphaltic cement is used in 
both cases. The binder course is constructed 1 to 2 in. thick after com- 
pression, depending upon the severity of the traffic. 

The open binder is prepared from broken stone, the fragments of which 
are largely of one size, ranging from | to 1 in. in diameter. No attempt is 
made to secure a graded aggregate or a dense mixture free from voids. 
Trap rock or hard and tough limestone (non-crystalline) is best suited for 
the purpose, although in certain cases granite may be used where the other 
rocks are not procurable. 

The average weight of crushed stone suitable for the binder course 
approximates 100 lb. per cubic foot, requiring SJ to 5^ per cent by weight 
of asphaltic cement. It is prepared and laid in the same manner as bitu- 
minous concrete pavements. The same asphaltic cement may be used in 
the open type of intermediate course as in the surface course (see p. 370). 

A close binder is better adapted to withstand heavy traffic than an 
open binder, and is now largely being used in place of the latter. It is 
prepared in the same manner as asphaltic concrete (see p. 262), and is 
laid in a course measuring 1 to 2 in. thick when compressed. Old asphalt 
pavements as they are removed from the street preparatory to resur- 
facing are often converted into close binder, as previously described, by 
heating with steam and mixing in broken stone and asphaltic cement to 
increase the percentage and soften the consistency of the cement present 
in the old mixture. 

Surface or Wearing Course. This is composed of a graded sand, filler 
and asphaltic cement. The durability of the pavement will depend: 

(1) Upon the care with which the mineral aggregate is graded. 

(2) Upon the percentage and characteristics of the asphaltic cement. 

The following points are of importance in arriving at the basis of a 
proper surface mixture : ^ 

(1) Aggregate passing a 200-mesh sieve. 

(2) Aggregate passing 80- but retained on a 200-mesh sieve. 

(3) Aggregate passing 40- but retained on an 80-mesh sieve. 

(4) Aggregate passing 10- but retained on a 40-mesh sieve. 

(5) Aggregate retained by a 10-mesh sieve, 

(6) Pure asphalt present (free from mineral constituents) 

1 For an explanation of the various sieves used, see p. 540. 



BITUMINOUS PAVING MATERIALS 
The following mixtures have given good results: 



369 





Specifications, Borough 
OF Manhattan. 


Richardson's 
Specifications. 


Fifth Ave., 
N. Y. City. 




Alcdium 
Traffic. 


Heavy 
Traffic. 


Medium 
Traffic. 


Heavy 
Traffic. 


Heavy 
Traffic. 


Passing 200-niesh . . . 


Per Cent. 
12-18 
10-30 
20-55 
10-35 



Per Cent. 
13-20 
13-30 
20-55 
10-30 



Per Cent. 
10.0 
18.0 
38.0 
24.0 
0.0 


Per Cent. 
13.0 
26.0 
34.5 
16.0 
0.0 


Per Cent. 
17 4 


Passing 80; retained 200.. . 
Passing 40; retained 80.. . 
Passing 10; retained 40... 


33.4 

32.1 

21.5 

3.7 






Asphaltic cement (pure) . . . 


9.5-12.5 


10.0-12.5 


10.0 


10.5 


10.6 



A proper!}'' balanced mineral aggregate should cont.an sufficiently fine material 
" passing 200-mesh/' to make the compressed pavement dense, tough, slightl}'- sus- 
ceptible to temperature changes, unaffected by water, and not liable to displacement 
in service. Too much material " passing 200-mesh " will cause the pavement to 
" ball up " and prevent it from spreading easily while in a heated condition; it is 
also apt to make the finished pavement " mushy " and liable to indentations; and 
it will consume an excess of asphaltic cement, at a correspondingly increased ex- 
pense. The fine material " passing 200-mesh " is usually added m the form of 
" filler," or " dust " (see p. 363), the quantity of which will depend largely upon 
whether or not the asphaltic cement itself contains mineral matter. Thus in the 
case of the Trinidad asphaltic cement, naturally containing a percentage of clay and 
sihca, 20 per cent less filler must be added than with a Bermudez asphaltic cement 
almost free from associated mineral constituents. The quantity of filler to be added to 
the sand should be regulated so that the surface mixture will contain not less than 10 
per cent " passing 200-mesh " when the pavement is to be subjected to moderate traffic 
conditions, nor more than 18 per cent, when intended to withstand heavy traffic. 

The aggregate must contain sufficient particles " passing 80 — but retained on a 200- 
mesh sieve " to overcome the tendency of the filler to " ball up " the surface mixture 
while it is being spread on the pavement, enabling the mixture to spread out easily and 
form a dense surface under compression, capable of resisting the action of water. 

The particles " passing 10 — but retained on a 40-mesh sieve " from the '' back- 
bone " of the pavement, as it were, preventing the mixture from becoming displaced 
in service, and forming a less slippery wearing surface. 

Asphaltic cement should be present in just sufficient quantity to completely fill 
the voids in the aggregate after compression. Too little will form a pavement 
lacking strength, and liable to crack upon being subjected to changes in tempera- 
ture. Too large a proportion will make the surface mixture ''mushy "so that the 
particles of sand are apt to become displaced under traffic. Modern practice calls 
for 9 to 17 per cent of asphaltic cement, depending upon the character of the aggre- 
gate and the conditions under which the pavement will be subjected. Richardson 
has patented a mixture containing at least 10 per cent mineral particles passing 
200-, 100- and 80-mesh sieves respectively, and not less than 10^ per cent pure 
asphalt.^ 

lU. S. Pat. 607,884 of Jul. 26, 1898 to Clifford Richardson. 



370 



ASPHALT AND ALLIED SUBSTANCES 



It is unusual to find one sand fulfilling all of the foregoing requirements. Gen- 
erally two or more sands must be blended together, and a suitable proportion of 
filler added, to produce an aggregate of the optimum characteristics. Richardson 
makes a special virtue of the fact that refined Trinidad asphalt contains naturally 
about 27 per cent filler composed largely of " colloidal " particles.^ In some cases 
an aqueous paste of " colloidal " clay is purposely added to pure asphalts to sim- 
ulate the Trinidad mixture. ^ Oklahoma rock asphalts carrying about 12 per cent 
of pure asphalt are well suited for constructing sheet asphalt pavements, as they 
are resistant towards atmospheric conditions and do not become brittle at low 
temperatures, thus resembling the Seyssel and Neuchatel asphalts. ^ It is estimated 
that 2j-13| million tons are available.^ 

The following figures show the relation between the percentages by weight and 
volume in a standard surface mixture.^ 





By Weight. 
Per Cent. 


By Volume. 
Per Cent. 




10.5 

13.0 

13.0 

13.0 

23.5 

11.0 

8.0 

5.0 

3.0 


23.1 

11.4 

11.1 

11.1 

20.0 

9.4 

6.8 

4.3 

2.8 


Passing 200-mesh sieve 




Passing 50-mesh sieve 

Passing 40-mesh sieve 








100.0 


100.0 



Asphaltic Cement. The asphaltic cement should be somewhat harder 
than that used in bituminous concrete pavements, complying with the fol- 
lowing characteristics : 

(Test 85) Float test at 150° F.s Less than 10 minutes 

(Test 96) Penetration at 115° F.e Less than 300 

Penetration at 77° F.* 25-45 

Penetration at 32° F.« Greater than 10 

(Test 10a) Ductility at 77° F. (Dow method) Greater than 20 

(Test 15o) Fusing-point (K. and S. method) ^ 90-120° F. 

(Test 156) Fusing-point (B. and R. method) « 105-140° F. 

1 " The Theory of the Perfect Sheet Asphalt Surface," Clifford Richardson, /. Ind. Eng. Chem., 
7, 463, 1915; " Importance of the Relation of Solid Surfaces and Liquid Films in Some Types 
of Engineering Construction," Clifford Richardson, Proc. Western Soc. Engineers, Chicago, Nov. 
20, 1916. 

2U. S. Pats. 1,198,769 and 1,198,955 of Sep. 19, 1916 to Clifford Richardson. 

' " Weathering of Rock Asphalts of U. S. in Pavements," S. F. Peckham, Trans. Am. Inst. 
Chem. Eng., 6, 245, 1913. 

« " Oklahoma Rock Asphalts for Paving," L. C. Snider, J. Soc. Chem. Ind., 34, 30, 1915. 

5 Private communication from Clifford Richardson. 

* The float, penetration and fusing-point tests apply to pure asphaltic cement free from mineral 
constituents. In the case of Trinidad asphaltic cement these tests should be performed on the por- 
tion soluble in carbon disulphide, since the presence of mineral matter increases both the hard- 
ness and the fusing-point of bituminous mixtures (see p. 346). This is important and should not 
be overlooked. 



BITUMINOUS PAVING MATERIALS 



371 



(Test 16a) Volatile matter at 325° F. in 5 hrs Les9 than 3% 

Penetration of residue Greater than j of the 

original penetration 

(Test 17a) Flash-point (Pensky-AIartens tester) Greater than 350° F. 

(Test 21a) Soluble in carbon disulphide: 

In the case of Trinidad asphaltic cement Greater than 65% 

In the case of other asphaltic cements Greater than 95% 

(Test 21b) Non-mineral matter insoluble: 

In the case of all asphaltic cements Less than 3% 

(Test 21c) Mineral matter: 

In the case of Trinidad asphaltic cement Less than 35% 

In the case of other asphaltic cements Less than 4% 

(Test 22) Carbenes Less than 2% 

(Test 23) Solubility of non-mineral' constituents in 88° 

naphtha Greater than 70% 

Typical asphaltic cements prepared from Trinidad and Bermudez asphalts, 
respectively, by fluxing the refined asphalt with a residual oil derived from a mixed- 
base petroleum test as follows: 



(Test 7) 
(Test 96) 



(Test 9c) 



(Test 9d) 
(Test 10b) 



(Test 11) 



(Test 15a) 

(Test 156) 

(Test 15c) 

(Test 16a) 

(Test 17o) 

(Test 19) 

(Test 21o) 

(Test 216) 

(Test 21c) 



(Test 22) 
(Test 23) 



Specific gravity at 77° F 

Penetration at 115° F 

Penetration at 77° F 

Penetration at 32° F 

Consistency at 115° F 

Consistency at 77° F 

Consistency at 32° F 

Susceptibility factor 

Ductility at 115° F 

Ductility at 77° F 

Ductility at 32° F 

Tensile strength at 115° F 

Tensile strength at 77° F 

Tensile strength at 32° F 

Fusing-point (K. and S. method).. . 
Fusing-point (B. and R. method).. . 

Fusing-point (Cube method) 

Volatile matter at 325° F. in 5 hrs 

Flash-point 

Fixed carbon 

Soluble in carbon disulphide 

Non-mineral matter insoluble * 

Mineral matter 

Total 

Carbenes 

Non-mineral matter insoluble in 88' 
naphtha 



Asphaltic Cement 


Asphaltic Cement 


Prepared from 


Prepared from 


Trinidad Asphalt. 


Bermudez Asphalt. 


1.26 


1.07 


180 


225 


65 


65 


15 


12 


2.6 


2.3 


7.9 


8.0 


53.7 


62.2 


45.2 


53.0 


15 


17.5 


21.5 


17 


1 





0.25 


0.5 


0.75 


1.1 


15 


14 


115° F. 


115° F. 


133° F. 


1341° F. 


148° F. 


150° F. 


2.5% 


3.2% 


398° F. 


340° F. 


6.1 


9.8 


65.7% 


97.6% 


4.8% 


2.1% 


29.5% 


0.3% 


100.0% 


100.0% 


0.4% 


0.2% 



71.2% 



76.8% 



* Including water of hydration (see p. 113). 



Paving cements have been patented composed of mixtures of gilsonite and 
residual oil having a penetration at 77° F. of 50 to 100^; also mixtures of native 

» U. S. Pat. 981,225 of Jan. 10, 1911 to Clifford Richardson. 



372 ASPHALTS AND ALLIED SUBSTANCES 

asphalts carrying loosely combined sulphur-compounds heated together with vul- 
canizable vegetable oils.^ 

Preparing and Applying the Wearing or Surface Course. The aggregate 
should be heated to a uniform temperature between 250 and 375° F., the 
asphaltic cement to a temperature between 250. and 350° F., and the two 
mixed together in the required proportions. A special form of mixer 
used for this purpose is illustrated in Fig. 117. The mixing is continued 




Fig. 117. — Mixer for Preparing Paving Composition?. 

for at least two minutes. The mixture is brought to the street in covered 
wagons, deposited at not less than 225 to 275° F. and raked into a layer 
which after compression with a roller weighing 8 to 10 tons, will form a 
wearing surface of uniform thickness from 1 to 2| in. depending upon the 
conditions to which the road will be subjected. Before the final rolling, 
the surface should be dusted with Portland cement or other fine 
powder. 

The deterioration of sheet asphalt pavements is due to: 

(1) Defective construction, including improper proportioning of the ingredients. 

(2) The actual wear and tear of traffic. 

(3) Aging due to exposure to the elements. 

1 U. S. Pat. 1,163,593 of Dec. 7, 1915 to C. N. Forrest. 



BITUIMIXOUS PAMXG MATERIALS 373 

(4) Unfavoralile environment including severe climatic conditions, water, illu- 
minating gas, etc. 

These defects, due to one cause or another will manifest themselves by cracks, 
general disintegration of the surface, formation of waves, depressions, holes, chip- 
ping or peeling of the wearing course, etc. 

Asphalt Block Pavements. These are similar in composition to the 
wearing course of sheet asphalt pavements, and in addition contain smaF 
broken stone or grit passing a |-in. screen but retained on a 10-mesh sieve, 
also fine filler. The Topeka specifications (p. 364) have been largely 
used for this purpose. It is advisable that there should be present at 
least 20 per cent of filler passing a 200-mesh sieve, and not more than 3 
per cent of grit retained on a l-in. screen. The aggregate should accord- 
ingh^ be composed of a mixture cf grit, sand (or mixture of sands) and 
filler, in such proportions as to secure the minimimi percentage of voids. ^ 

From 6 to 9 per cent of asphaltic cement should be used, having a lower 
penetration than the cement used in the surface mixture of sheet asphalt 
pavements (p. 370) but of a higher fi.:sirg-pcint (i.e., 175 to 200° F., 
B. and R. method. Test 156) to prevent the blocks becoming distorted 
during transportation, or when exposed in piles to the heat of the sun. 

The blocks usually measure 12 in. long by 5 in. wide, and either 2, 2|, 
3, 4 or 5 in. deep. They are made by compressing in molds at a moderately 
high temperature (300° F.) under a pressure cf 2 to 3 tens per square inch. 
Their specific gra\dty at 60° F. should net be less than 2.50 if trap-rock 
grit is used, nor less than 2.35 when the grit is composed cf limestone. 

Foundation or Base. Asphalt blocks may be laid on a foundation 
consisting of gravel, macadam or preferably concrete. The foundation 
course should be covered with a " cushion " or '' bedding course," composed 
either of sand 1 in. thick, or cement mortar J in. thick, and the blocks 
embedded in the latter before it commences to set. 

Laying the Blocks. Blocks are laid close together, resting on the 12 
by 5-in. surfaces extending lengthwise across the street, the joints being 
broken 4 in. They should be wedged together as firmly as possible to 
close the joints between them, and rammed into place. After being 
laid, the blocks are given a light coat of sharp, fine sand, well broomed 
into the joints, and the pavement opened to traffic in three to four days. 

Asphalt blocks have improved greatly in the last few years and are now capable 
of withstanding severe traffic conditions without fracturing. They are slightly 
more expensive than a sheet asphalt pavement, but permit repairs being effected 
more readilj^, and insure a more uniform composition also a greater freedom from 
structural faults. 

lU. S. Pat. 853,110 of :May 7, 1907 to Clifford Richardson. 



374 ASPHALTS AND ALLIED SUBSTANCES 

The great difficulty encountered in proportioning the blocks is to manufacture 
them sufficiently hard and infusible to withstand transportation, and at the same 
time prevent the pavement being brittle in service. This may be effected by using 
a binder having a moderate penetration and a high fusing-point. When properly 
made, the blocks will weld together after a time, upon being subjected to traffic, 
so that the joints between them will become almost invisible. Sometimes they are 
anchored in place with metal rods to prevent the blocks shifting. If the binder is 
too hard and brittle, instead of the blocks welding, the edges will chip and spall. 
On the other hand, if the binder is too soft or fusible, the blocks will lose their 
shape, becoming distorted, even before they are laid in place. 

Asphalt tiles suitable for paving floors and sidewalks are prepared in a similar 
manner. They are stamped out in square or hexagonal units. The large square 
(8X2J in.) or hexagonal (10X2| in.) tiles are laid on a foundation consisting of 
6 to 8 in. of gravel and sand, and the small hexagonal tiles (6X1 in.), are laid on a 
3-in. foundation, in either case surfaced with | in. of mortar. 

Asphalt Mastic Foot-pavements and Floors. In the United States, 
asphalt mastic is restricted to the construction of foot pavements and 
floors, for waterproofing railway bridges (p. 432), also for lining reservoirs 
and tanks. In composition, it is similar to the Topeka asphaltic concrete 
(p. 364), but it contains a larger percentage of asphaltic-cement, so that 
it may be laid with greater facility. It is differentiated from bituminous 
concrete, sheet asphalt pavements, etc., by the fact that the asphalt 
mastic on being heated forms a thick and slowly flowing mass which may 
be 'poured into place. The mixture on being allowed to cool partially, 
is compressed by hand-trowelling to a smooth surface. Asphaltic con- 
crete and sheet asphalt pavements on the other hand, do not melt when 
heated, but form an adherent, powdery mass, which upon being shovelled 
into place and raked smooth, require compression underneath heavy 
rollers, to properly compact them. 

Asphalts Used. Asphalt mastic work constituted the earliest type of 
asphalt pavement (p. 15), and few changes have been made in its mode 
of application since the inception of the industry. The first products 
used in asphalt mastic construction were the native " rock asphalts," 
including Val de Travers, Limmer, Seyssel, and later on Ragusa. The 
refined rock asphalt (previously heated to expel the moisture and volatile 
oils) was first ''cooked " over an open fire in a suitable melting tank provided 
with a stirrer, and combined with a purer native asphalt, as for example 
Trinidad (of which about 8 or 10 per cent was used), Bermudez, or with a 
residual asphalt, so the finished batch carried 12 to 18 per cent of pure 
asphalt, the ba ance being composed of finely divided mineral matter 
(calcium carbonate, silica, iron and aluminium oxides, etc.). The cooking 
was performed at 350 to 400° F. The mass was then run into suitable 
molds and thus cast into flat cakes weighing 50 to 60 lb. each, customarily 



BITUMINOUS PAVING MATERIALS 875 

stamped with the name of the asphalt used. These cakes were known as 
^' rock asphalt mastic." To-day they are prepared from Trinidad asphalt, 
mixtures of asphaltites and flux, blown petroleum asphalts and residual 
asphalts, combined with calcium carbonate or finely powdered silica, 
all the ingredients being combined at once in a portable rotary mixer. 
The native rock asphalts first mentioned are all still being used abroad. 

The cakes of mastic upon being transported to the place where they 
are to be used, are melted with an additional quantity of '' flux," ^ 
and mixed with sand and fine gravel or " grit," in the proportion of about 

3 lO 3. 

A brand of mastic flooring prepared from a mixture of asphaltite and residual oil, 
which has given very good results in service, was found on analysis to contain 
15 per cent of pure asphalt, which in turn tested as follows: 

(Test 9a) Penetration at 115° F 30 

Penetration at 77° F 11 

Penetration at 32° F 10 

(Test 9c) Consistency at 115° F 13.0 

Consistency at 77° F 25 . 7 

Consistency at 32° F 55 . 4 

(Test 9d) Susceptibility factor 21.5 

(Test 15a) Fusing-point (K. and S. method) 197° F. 

(Test 156) Fusing-point (B. and R. method) 219° F. 

Methods of Preparation. A well-known manufacturer recommends the following 
proportions : 

" The mixture shall consist by weight of: 

Rock asphalt mastic From 55 to 57 parts 

Sharp dry sand and grit From 36 to 38 parts 

Flux From 9 to 5 parts 

Total 100 100 

" The sand and grit to be dry, sharp and so graded that the voids shall be re- 
duced to a minimum, none of the particles running over ^-in. in diameter 

these materials to be mixed in mastic kettles in the usual manner (the kettle tem- 
perature at no time to exceed 400° F.), and spread at a temperature of from 300® 

to 325° F After spreading and as the hot mastic cools and sets, it shall be 

lightly sprinkled with hard sand and rubbed up to a smooth surface finish by means 
of the usual smoothing tools or floats." (Fig. 118). 

The rock asphalt mastic contains 16 per cent by weight of pure asphalt, and the 
finished mixture including the flux is composed of the following: 

Pure asphalt 17.8- 14.1% 

Finely divided mineral matter present in mastic 46.2-47.9% 

Sand and grit added 36.0- 38.0% 

Total 100.0-100.0% 

1 The " flux " may consist either of refined Trinidad asphalt, or its equivalent (fusing at about 
190° F., K. and S method), for hardening mastic floors subjected to high temperatures, or a mode- 
rately soft asphalt (fusing between 135 and 155° F., K. and S. method; penetration at 77° F.: 
40 to 80; ductility by Dow method at 77° F.: 10 to 30) for softening the mastic where the floors 
must remain elastic under reduced temperatures. 



376 



ASPHALTS AND ALLIED SUBSTANCES 



The quantities required to lay 1 cu. yd. (equivalent to 324 sq. ft. 1 in. thick) 
are as follows: 



Rock asphalt mastic 

Sand and grit 

Flux 

Total 



Flured Gilsonite 

Mastic, 

Lbs. 

2170-2170 

1430-1455 

275- 200 



3875-3825 



Limmer or 

Vorwohle Mastic, 

Lbs. 



2540-2680 

1195-1350 

165-170 

3900-4200 




The Limmer and Vorwohle rock asphalt mastics contained 15 per cent of pure 
asphalt, and the finished composition 13.6-14.2 per cent. 

The completed mixture contains therefore twice as much asphaltic cement as an 
asphalt concrete pavement, which accounts for the fact that the mastic may be 

melted and poured. The finely divided mineral 
matter present in the rock asphalt mastic assumes 
the role of " filler." The flux is not combined 

!mW\ ^-J^^^fe inJ II ^^^^ ^^^ ^^^^ asphalt mastic in the original 

LLLJiiD ^^^^^ ^ M j process of manufacture because it is necessary 

II to vary the consistency of the mastic for differ- 

^' ' ent purposes, by adding a larger or smaller 

proportion of the flux. 

Mastic floors and pavements may be laid 
over wood, concrete or masonry, in thicknesses 
varying from 1 to 2 in., depending upon the 
amount of traffic to which they will be subjected. 
If the floor is over 1 in. thick, the mastic should 
be laid in two layers of equal thickness, breaking 
joints. When laid over wooden floors, a sheet 
of tar- or asphalt-saturated felt (p. 397) is 
first applied to prevent any trouble resulting 
from the wood shrinking underneath the mastic. 
When used for pavements out of doors, the 
mastic should be laid on a Portland-cement 
concrete foundation not less than 3 in. thick. 
Additional formulas based on the use of 
mastic prepared from Trinidad asphalt proportioned so the finished mixture will 
carry approximately 12 per cent of pure asphalt, are included in Table XXXI. 

The ingredients are combined in a kettle over direct fire heat, with continual 
stirring to prevent local overheating or carbonization, or in a mechanical mixing 
machine having a rated capacity of 185 sq.ft. of finished mastic 1 in. thick per 
hour. The mixture is dipped from the kettle or mixer with iron buckets and poured 
upon the dry and properly graded foundation. Its consistency is such that it will 
flow slowly, and the spreading and smoothing are performed with the trowels, the 
operation being similar to plastering. 

When the flooring is apt to come in contact with acids, in manufacturing estab- 
lishments or storage battery rooms, the rock asphalt mastic must be prepared with 



Steel hooped wooden' pail for measuring 

sand and grit and for carrying hot mixture. 

Mixing and cooking kettle. 

Stirrer for agitating hot mass in kettle. 

Shovel for taking hot mixture from kettle. 

Spatula or sprsading tool. 

Float or smoothing tool. 



Fig. 118. — ^Tools for Finishing Mastic 
Floors. 



BITUMINOUS PAVING MATERIALS 



377 



TABLE XXXI 



Proportions by 
Weight. 



Sidewalks 

Corridors, toilets, 
stair treads 

Cellars and store | 
rooms, not rold \ 
storage J 

Shops, (light traf- 
fic, etc.) 

Cold storage 

Freight houses, 1 
platforms, lail- I 
road shops and I 
driveways J 

Cold storage: 
Bottom course 1 
Top course > 

Top course J 

Plating and acid 

Tank rooms: 

Bottom course \ 
Top course J 

Reservoirs' 

Swimming pools: 
Walls and floois 

R. R. Bridges (over 
membrane water- 
proofing): 
Bottom course 

Top course 



g a waterproof- 
ing course alone: 
Both courses 



Concrete bridges 
on arches and 
under pave- 
ments 

Magazines and 
loading rooms 
not neavy traffic 

Fillets and coves 
Acid tanks 





o ^ 

O i. 


Ma 


Stic. 


a 




Mineral Aggregate. 


c 

o 

1 


33 
40 

■15 

50 
45 

50 

40 
45 
50 

CO 

eo 

60 
50 

65 

55 


1 




d 

c 

C 

a. 




"C 

o 


1 
■< 


« 




1 
1 

1 

1 
1 

1^ 

fl:' 

li 

n 

n 

1 

1 

1^ 
n 






6 
5 




20 
15 

15 

12 
15 

12 

20 
15 
12 

15 

12 
5 

5 

5 
12 

5 

10 

45 


41 
40 

35 

33 
35 

33 

35 
35 
34 

35 
33 
30 

31 

CO 
33 

25 

30 




61 
55 

50 








Concrete 




5 
5 










45 
50 

45 

55 1 
50 I 
46 

50 
45 
35 

36 




5 












5 
5 

4 

5 




Wood or 






Cork 






Concrete 
f r AVood 


45 
cO 


5 


Concrete 


5 
4 

5 
5 

5 

5 
10.3 


35.2 














8.r 


35 
45 

CO 

40 

73.7 
45 














Concrete 






Concrete 




16 
5 




50 




Concrete 










Wood 









































Remarks. 



Foot traffic only. 
One-half hard flux 
sometimes. 



Preferably in two 
I in. layers. 

Preferably in two 

layers 
If under heavy 

traflBc. 

Cne-half hard flux 

sometimes. 
Mastic protected 

with concrete or 

brick. 
Pack cf and under 

enarrelcd brick 

facing. 

Laid on paper or 
dry felt. 

Top course mop- 
ped with heavy 
coat of Trinidfid 
asphalt cen;ent 
and sanded. 

Top protected 
with concrete or 
preferably brick 
with asphalt 
joints. 

Applied on a 
primer coat of 
cold liquid as- 
phalt. 

Ungritted mastic. 



Against walls, 
columns, etc. 

Mixtures and ap- 
plication vary 
with conditions. 



878 ASPHALTS AND ALLIED SUBSTANCES 

finely bolted silica as filler in place of calcium carbonate. Where the wear is par- 
ticularly severe or a specially durable floor or pavement is to be constructed, the 
mastic is customarily laid on a metal frame or grid, which becomes embedded in the 
floor and reinforces it in the same manner as the reinforcing metal in concrete 
The metal becomes exposed as the floor wears down and retards further attrition. 

Asphalt mastic may also be used for constructing foundations of engines, trip- 
hammers, or other heavy vibrating machinery, to deaden sound and concussion. 
In this case 40 per cent by weight of the mastic is mixed with 60 per cent by 
weight of broken stone, and tamped into place. It also finds a particular sphere 
of usefulness for waterproofing railway bridges subjected to severe vibration (see 
p. 432). 

In Europe, asphalt mastic is also used for finishing the roofs of buildings, applied 
in two layers totalling f to 1 in. thick, also" for the construction of subgrade water- 
proofing, including the " dampcourse " of buildings. It does not, however, give 
satisfactory results on vertical surfaces exposed to the weather. 

Bituminized Wood-block Pavements. Creosoted wood-blocks are 
being used extensively for paving roads, foot-paths, floors of buildings, 
etc. 

Methods of Impregnations. The '^ Proposed Tentative Specifications 
for Wooden Paving Blocks " issued by the American Society for Testing 
Materials, 1917, provide that: 

" The wood, which shall be treated, shall be Southern yellow pine, Douglas fir, 
tamarack, Norway pine, hemlock, or black gum. Only one kind of wood shall be 
used in any one contract. The blocks shall be sound and must be well manufac- 
factured, square-butted, square-edged, free from unsound, loose or hollow knots, 
knot holes, worm holes, and other defects such as shakes, checks, etc., that would 
be detrimental to the blocks. 

The number of annual rings in the 1-in. which begins 2-in. from the pith of 
the block shall not be less than six, measured radially; provided, however, that 
blocks containing between five and six rings in this inch shall be accepted if they 
contain 331 per cent or more summerwood. In case the block does not contain 
the pith, the 1-in. to be used shall begin 1-in. away from the ring which is nearest 
to the heart of the block. The blocks in each charge shall contain an average of 
at least 70 per cent of heartwood. No one block shall be accepted that contains 
less then 50 per cent of heartwood." 

The size of the blocks ranges as follows: 

Depth between 3 and 4 in. depending upon the severity of the traffic to which 
they are to be subjected, usually 3 in. for light traffic, 3| for medium and 4 in. for 
heavy traffic conditions. 

Width should be uniform for any particular pavement, but may vary between 
3 and 4 in. The best practice provides that there should be a difference of not 
less than \ in. between the width and the depth, which under no circumstances 
should be made equal. 

The length will vary in any particular lot, between 5 and 10 in,, averaging about 
8 in. Blocks 3 in. deep should not exceed 8 in length, blocks 3| in. deep should 
not exceed 9, and blocks 4 in. deep should not exceed 10. 



BITUMINOUS PAVING MATERIALS 379 

After removing the bark, the wood is cut into planks equalHng in thickness tlie 
width of the finished block. The planks are then run through a planer, trimming 
them all to exactly the same size (insuring a uniform width of the finished blocks), 
and finally through a set of gang-saws, which cuts them into the finished blocks. 

Formerly, the wood was seasoned out of doors from four to twelve months, 
depending upon the kind of wood, its dimensions, the season of the year and the 
locality. At the present time this process is accelerated by steaming the blocks 
for two to four hours in steel cylinders varying in size from 6 ft. in diameter by 
42 ft. long, to 9 ft. in diameter by 172 ft. long. In this treatment, live steam is 
introduced at not exceeding 20 lb. pressure per square inch, raising the tempera- 
ture between 220 and 240° F. After the steaming, the cylinder is subjected to a 
vacuum of not less than 22 in. maintained for at least one hour, to withdraw the 
moisture and resinous matters. This is continued until the blocks are thoroughly 
dry, whereupon the creosote oil heated to 180-220° F., or a mixture containing 80 
per cent zinc chloride and 20 per cent creosote ^ is introduced. The pressure is 
applied gradually, not to exceed 50 lb. at the end of the first hour, nor 100 lb. at 
the end of the second hour, and then maintained at not less than 100 nor more 
than 150 lb. until the proper impregnation has been attained. The oil is pumped 
from the cylinder and the blocks allowed to drain for about a half hour at a 
temperature of 200° F. under a vacuum of at least 20 in. The quantity of pre- 
servative introduced should range between 6 and 12 lb. per cubic foot with blocks 
used for floors, and from 12 to 20 lb. per cubic foot, averaging 16 lb., with blocks 
used for paving roads. The function of the preservative is twofold, namely: 

(1) To prevent the wood from decaying, due to the ravages of fungi and moulds. 

(2) To waterproof the blocks, preventing them from warping or swelling. 

Ten pounds of the preservative per cubic foot are sufficient to preserve the blocks 
from decay, although a larger quantity must be used to secure the required water- 
proof properties. To completely waterproof the blocks 25 lb. would be required, 
which is more than ordinarily used in practice. 

Creosote Preservatives. The so-called " creosote " preservatives include 
the following products: 

(1) Distillates from gas-works coal tar or coke-oven coal tar, known 
commercially as " distillate oil." 

(2) Mixtures of the foregoing " distillate oil " with not exceeding 
35 per cent of a gas-works coal tar or coke-oven coal tar, containing 
preferably 5, but not exceeding 25 per cent free carbon.^ Refined 
or filtered tars are recommended for this purpose. 

In using the creosote, care should be taken to prevent it becoming 
contaminated with water. ^ 

The creosote preservative shall comply with the following specifications, where A 
and B represent a pure distillate from gas-works coal tar or coke-oven coal tar; and 
where C, D and E represent mixtures containing at least 65 per cent distillate oil 
from gas-works coal tar or coke-oven coal tar, and the balance a low carbon gas- 

1 U. S. Pat. 815,404 of Mar. 20, 1906, to J. B. Card. 
^Proc. Am. Wood. Pres. Assoc, 16, 825, 1915. 
Ubid., 827, 1915. 



380 



ASPHALTS AND ALLIED SUBSTANCES 



works coal tar or coke-oven coal tar. Specifications A and C are published by the 
Committee on Wood Preservation ^; D by the Committee on Standard Specifica- 
tions of the Creosoted Wood Paving Block Bureau 2; whereas B and E constitute 
tentative specifications of the American Society for Testing Materials.^ 



Sp.gr. at 38° C. (Test 7d) 

Vis?csity (Engler method) at 82° C/20°C. (Test 8a) 

rixed carbon (Test 19) 

Distillation test (Teat 20): 

Up to 210° C 

Up to 235° C 

Up to 315° C: 

Up to 355° C 

Sp.gr. distillate 235-315° C. at 38° C./15.5° C. 
Sp. gr. distillate 315-355° C. at 38° C./15.5° C. . . 
Sp.gr. residue above 355° C. at 25° C./15.5° C. . . 

Insoluble in hot benzol (Test 24) 

Water (Test 25) 



>1.06 
<1.15 



<5% 
<15% 



>1.02 
>1.09 

* 

<0.5% 



B 



>1.06 
<1.15 

<2% 

<5% 
<15% 



> 1 . 03 
>1.09 
* 

<0.5% 
<3% 



1.06-1.12 
<1.3 



<5% 
<30% 
35-70% 
>65% 
>1.02 
>1.08 

t 
<3% 
<3% 



1.07-1.11 
<1 2 



<5% 

<30% 

>50% 

>70% 

>1.03 

>1.08 

>1.23t 

<2.5% 

<3% 



1 . 07-1 . 14 

<10% 

<5% 
<25% 



>1.03 
>1.09 
t 

<3% 
<3% 



* If >10%, the residue shall have float test at 70° C. of <£0 seconds. 

t If >35%, the residue shall have float test at 70° C. of <80 seconds. 

I If residue is crystalline, granular and non-ductile, it shall have a, specific pravJty of <1.14 
at 25° C./15.5° C. 

The city of Chicago specifies: (1) That the creosote oil shall have a specific 
gravity of 1.10-1.14; (2) less than 22 per cent shall distil below 236° C, and less 
than 40 per cent below 315° C; (3) the residue after distillation to 355° C. shall 
be plastic and not brittle at 77° F., and shall produce a clear amber-colored spot 
on filter paper when warmed; (4) the distillate obtained between 250° and 315° C. 
shall contain not less than 5 per cent of tar acids nor more than 1| per cent of 
unsaponifiable matter. 

Mixtures of distillate oil with a certain proportion of refined tar are supplanting 
the use of the oil alone, for the reasons that: 

(1) They are less expensive. 

(2) They waterproof the blocks more efficiently. 

(3) They volatilize less readily. 

The presence of too much tar in the creosote mixture interferes with the pene- 
tration, due to the fact that the tar has a greater viscosity than the distillate oil 
at high temperatures. An excess of free carbon in the tar will clog the pores of the 
blocks and similarly interfere with the penetration. 

Foundation Course. This will vary in thickness depending upon the 
traffic, consisting of a Portland-cement concrete 5 to 9 in. thick, 
usually averaging 6 in. A 1 : 2J : 5 concrete with a smooth-trowelled 
finish is recommended. 

Cushion Layer. The best practice requires the blocks to be em- 
bedded either in a '' cushion " or Portland-cement mortar, or a thick 



coating of tar and sand. 



Where mortar is used, the blocks are laid in 



i Proc. Am. Wood. Pres. Assoc, 29, 1916. 

^ Proc. Am. Wood Pres. Assoc, 2, 44, 1915. 

8 Proc, Am. Soc. Testing Materials, 1917, Standards, 



BITUMINOUS PAVING MATERIALS 381 

a 1 : 4 Portland cement mortar ^ to 1 in. thick. ^ The mortar should be 
prepared as dry as possible and the blocks rammed into place, forming 
a level surface free from depressions. The pavement must be closed to 
traffic until the cement mortar sets. 

Where the blocks are to be embedded in a tar cushion, a thick 
coating of heated tar is spread on the concrete foundation and while hot 
sprinkled with sand, forming a mastic into which the blocks are rammed. 

The English practice, which now seems to be gaining favor in this 
country, consists in constructing the foundation course as smooth and 
level as possible, laying the blocks in place, and pouring hot tar between 
the crevices. The tar will first work its way underneath the blocks and 
cement them to the foundation, and the pouring is continued until the 
joints are filled half way to the surface. The joints are then filled 
with a grout of Portland cement. This procedure prevents " bleeding." 

The blocks may be laid in rows either perpendicular to the curb, or at angles 
varying from 45° to 67^°, the latter having the advantage of conforming to the 
expansion and contraction of the pavement without the necessity of providing trans- 
verse expansion joints. Where the blocks are laid at right angles to the curb, V in. 
transverse expansion joints (page 384) should be introduced every 50 or 60 ft. 
In all cases, an expansion joint | in. wide, should be provided between the blocks 
and the curb, composed either of a preformed bituminous strip (p. 383) or a melted 
bituminous mixture having a penetration of 30-40 at 77° F. (Test 96). The blocks 
must be laid as close together as possible, with joints not exceeding | in., and levelled 
with a roller weighing not less than 4 tons. 

Filling the Joints. Three types of fillers are employed for wooden 
paving blocks, viz.: sand, Portland-cement grout or a melted bitumi- 
nous composition. The last named is used most frequently.^ When 
dry sand is selected, it should be of a fine texture and spread with 
a broom. Sand is the least eflQcient form of filler, but in time it will 
mix with the creosote oil or tar exuding or '' bleeding" from the blocks, 
and form a mastic between the joints. 

Portland-cement grout should be composed of equal volumes of 
cement and fine sand, made up with water to a fairly liquid consist- 
ency, and after being swept into the joints, the pavement should be 
closed to traffic until it sets. 

The characteristics of the bituminous filler will be described on 
p. 382. It is swept on the surface in a melted condition, and has the 
advantages of augmenting the waterproof properties of the blocks, at 
the same time providing for their expansion and contraction. The 
bituminous filler is covered with sand or chips or with a cement grout, 
to obviate any tendency of the pavement tracking. 

^ Eng. Record, 73, 154, 1916. 2 U. S. Pat. 71,746 of Dec. 3, 1867 to Alexander Hamar. 



382 



ASPHALTS AND ALLIED SUBSTANCES 



General Considerations. A wood-block pavement when properly constructed is 
extremely durable even under heavy traffic; it may readily be repaired and is less 
noisy than any other bituminous pavement. The disadvantages are its slipperiness 
in damp or snowy weather, and the fact that under certam conditions it is apt to 
" bleed." The latter manifests itself by the soft bituminous matter exuding in 
summer, and being readily tracked about. 

Bleeding is caused by introducing too large a proportion of the creosote mixture 
into the blocks, and is likely to occur when more than 16 lb. are used per cubic foot. 
It will also occur when the pavement is not provided with expansion joints, in 
which event the compression brought about by expansion, will squeeze some of the 
creosote from the pores of the blocks. 

Bituminous Fillers for Wood, Brick and Stone Pavements. A " bitu- 
minous filler " is the name applied to a bituminous substance introduced 
into the joints of wood-block or brick or stone pavements by melting 
and pouring. It must adhere to the bricks or blocks in cold weather 
without loosening or chipping under the impact of traffic, or when 
subjected to strains brought about by contraction or settling of the 
pavement. The filler must accordingly possess great adhesive strength 
and ductility, and must also be sufficiently resistant to high tem- 
peratures not to exude from the surface, or run out of the joints. 

Characteristics of Bituminous Materials Used. The same classes of bituminous 
materials have been used for fillers as the bituminous cements of bituminous con- 
crete pavements (p. 365), and they should comply with the following characteristics: 



Asphaltic Fillers. 



Pitch Fillers. 



(Test 96) 


(Test 10a) 


(Test 11) 


(Test 15a) 


(Test 156) 


(Test 15c) 


(Test 16a) 


CTest 17a) 


(Test 20) 


(Test 21a) 


(Test 216) 


(Test 21r) 


(Test 22) 


(Test 23) 



Penetration at 115° F 

Penetration at 77° F 

Penetration at 32° F 

Ductility at 115° F 

Ductility at 77° F 

Ductility at 32° F 

Tensile strength at 115° F 

Tensile strength at 77° F 

Tensile strength at 32° F 

Fusing-point (K. and S. method) 
Fusing-point (B. and R. method) 

Fusing-point (Cube method) 

Volatile at 325° F. in 5 hrs 

Volatile at 500° F. in 4 hrs 

Flash-point 

Distillate under 600° F 

Soluble in carbon disulphide 

Non-mineral matter insoluble. . . . 

Mineral matter 

Carbenes 

Soluble in 88 ' naphtha 



<150 

25-60 

>20 

>50 

>10 

>\ 

>0.25 

>2.5 

>7.5 
140-160° F. 
160-180° F. 



<2% 
<5% 
>350° F. 



>98% 
<2% 
<1% 
<2% 
65-75% 



>50 

>10 

>\ 

>0.25 

>2.5 

>7.5 



130-140° F. 

<5% 
<8% 
>350° F. 

<8% 
60-80% 
20-40% 

<1% 

<5% 



N.B. Pitch fillers in view of their low fusing-point should only be used where the 
joints between the bricks or blocks are to be filled with fine gravel, which will serve 
to hold the pitch in place. 



BITUMINOUS PAVING MATERIALS 383 

Filling the Jcints. With brick and stone block pavements, the 
courses should be laid with joints f to J in. wide. When a pitch filler 
is to be used, the joints are half filled with | to f in. hot gravel (con- 
taining not over 25 per cent of the |-in. size). Before the gravel cools, 
the joints should be filled half way to the top with filler, then to within 
5 in. of the surface with hot gravel, and lastly poured full with filler. 
In performing the work, the pitch should be heated from 250 to 325° F., 
but never exceeding the latter. When asphaltic filler is used, sand or 
gravel are unnecessary. The filler is heated from 300 to 450° F. and 
poured into the joints until completely filled. A top dressing of sand 
should be spread over the filler while hot to form a wearing surface. 

The joints of wood-block pavements are formed as closely as possible, and the 
melted filler poured over the entire pavement and worked into the joints until fiush 
by scraping with a wooden or rubber squeegee, or a broom, whereupon the entire 
pavement is sprinkled with fine sand or gravel. 

Bitixminous Expansion Joints. These are composed of bituminous 
strips I to li in. thick, made up with or without a felted or woven 
fabric or metal reinforcement. They are used in connection with con- 
crete or block pavements and installed between the pavement and curbs, 
also transversely across the pavement to take up the expansive and 
contractive stresses and strains. When expansion joints are not used, 
a concrete pavement will crack in cold weather because of the inelasticity 
of the concrete, and have a tendency to buckle or bulge in hot weather. 

Modern practice calls for longitudinal expansion joints along the 
curbs, and transverse joints spaced at intervals of 40 to 75 feet. The 
width of the expansion joint should equal the thickness of the pavement (3 
to 8 in.) 

Four types of bituminous expansion joints are in use, viz.: 

(1) Premoulded Strips of high Fusing-point Bituminous Compositions. These ^ con- 
sist of blown asphalt of a high fusing-point (50 parts) mixed with sand (50 parts) 
and shoddy-dust (25 parts); or of a bituminous mixture ^ cast in moulds 6 ft. long, 
whose thickness corresponds to the size of the joints (| to Ij in.) and width to the 
thickness of the pavement (3 to 6 in.). The approved mixture consists of grahamite 
21 per cent, residual oil derived from non-asphaltic petroleum 49 per cent, and soft 
native asphalt 30 per cent. The presence of the soft native asphalt enables residual 
oil derived from non-asphaltic petroleum to flux with the grahamite. The fusing- 
point of the combination should be in excess of 190° F. (Ball and Ring method). 
The mixture is claimed to possess the required elasticity, cohesiveness and resistance 
to temperature changes. In winter, however, the strips must be transported very 
carefully for they would break into small pieces if allowed to drop. 

>U. S. Pat. 1,134,939 of Apr. 6, 1915 to James Panwell. 
'U. S. Pat. 1,207,524 of Dec. 5, 191G, to C. N. Forrest. 



384 ASPHALTS AND ALLIED SUBSTANCES 

Longitudinal strips shaulcl be ^ in, thick for streets less than 20 ft. wide, f in. 
for streets 20-30 ft., 1 in. for streets 30-40 ft. and 1| in. for streets over 40 ft. 
wide, placed parallel with, and at each curb line. Transverse joints i to | in. 
thick should be spaced not less than 40 ft., and extend the full width of the brick, 
wood, stone block or concrete pavement. 

A proprietary product composed of gilsonite fluxed with blown petroleum asphalt 
tests as follows: 

(Test Qb) Penetration at 115° F 50-60 

Penetration at 77° F 35-40 

Per.etration at 32° F 20-30 

(Test 156) Fusing-point (B. and R. method) 240-255° F. 

(Test 21u) Soluble in carbon disulphide 99 . 5% 

The Commission of Highways of the State of New York, in specifications issued 
April 1, 1916, stipulate that the expansion joint should project at least f in. above 
the finished surface of the pavement at all transverse jomts. They also specify 
the premoulded joint to test as follows: 

(Test 7) Specific gravity at 77° F . 98-1 . 05 

(Test 96) Penetration at 115° F Less than 45 

(Test 96) Penetration at 77° F 15-35 

(Test 96) Penetration at 32° F Greater than 12 

(Test 156) Fusing-point (B. and R. method) 220-250° F. 

(Test 16) Volatile matter 5 hrs. at 325° F Less than 1% 

(Test 21a) Soluble in carbon disulphide Greater than 98.5% 

(Test 24) Soluble in carbon tetrachloride Greater than 99.8% 

(Test 24) Soluble in 76° naphtha 50-75% 

A modific:ition consists in comingling felted fibres with the bituminous matter in 
the presence of water, by forcing them through a perforated plate, and after evapo- 
rating the water, moulding the mixture to form the jomt.^ 

(2) Joints Composed of a Thick Layer of Bituminous Material Reinforced on Either 
Surface with Sheets of Plain or Bituminized Fabric. This joint is composed of two 
layers of untreated felted fabric, ^ or woven fabric impregnated with asphalt ^ (page 
408) and carrying a relatively thick layer of bituminous composition between, 
similar to the foregoing. The function of the fabric is to strengthen the joint, and 
enable it to be transported in cold weather without danger of fracturing, thus over- 
coming the objection against the foregoing type. The bituminous layer in the centre 
should have a high fusing-point (above 185° F., K. and S. method) and preferably a 
low susceptibility factor. It may be composed of asphaltic constituents, sometimes 
mixed with 25 to 59 per cent of finely divided mineral matter (calcium carbonate, 
shale, clay, silica, fuller's earth or slate), or from 15 to 30 per cent by weight of 
ground wood (" wood flour ") or fibrous matter. The function of the filler is to 
increase the toughness and resistance of the mixture to temperature changes (see 
page 346), and in certain cases to reduce the cost. 

The joint is manufactured in a continuous sheet on a form of roofing machine 
(d. 405), in which the two layers of bituminous felt previously impregnated with 
saturant (p. 395) are fastened together by introducing the melted or plastic bitumi- 
nous composition in between, carefully adjusting the thickness of the assembled sheet 

lU. S. Pats. 1,156,122 of Oct. 12, 1915, 1,166,166 of Dec. 28, 1915 and 1,240,524 of Sept. 18, 
1917, to J. C. Woodley; 1,177,267 of Mar. 28, 1916 to R. P. Perry. 
2U. S. Pat. 1.040,093 of Oct. 1, 1912 to James Adkins, Jr. 
3U. S. Pat. 1,248,909 of Deo. 4, 1917, to H. B. Pullar. 



BITUMINOUS PAVING MATERIALS 385 

to correspond with that of the joint desired. The width of the sheet should similarly 
correspond to the length of the completed joint (usually 6 ft.). When the assembled 
sheet has cooled, it is cut transversely with mechanically actuated knives, into 
strips 3 to 6 in. wide, depending upon the thickness of the pavement for which 
they are intended. In cross-section a paving joint of this type corresponds with 
" Type E," Fig. 199 (p. 561), with the intermediate layer of substantial thickness 
and coatings omitted. 

(3) One or More Layers of Bituminized Fabric, the Latter Cemented with a Bituminous 
Adhesive. One form of paving strip is composed of a single layer of tarred felt 
(p. 395);^ another consists of a strip of a woven fabric saturated and coated with 
asphalt, having particles of cork or sawdust embedded on the surfaces 2; and s(ill 
another is composed of three or more layers ^ of asphalt-saturated felt (p. SC5) 
cemented together with comparatively thin layers of an asphaltic adhesive. The 
strip when assembled varies from | to f in. thick, and the raw felt sheets range from 
No. 50 to No. 75 on the felt marker's scale (p. 389). 

In manufacturing this form paving joint, one or more webs of felted fabric are 
first impregnated individually with melted asphalt, usually quite soft in consist- 
ency (fusing-piont 90-140° F., K. and S. method), and are then joined by com- 
paratively thin layers of a harder asphaltic mixture (fusing-point 140-180° F., K. and 
S. method). The outer surfaces are not coated. The width of the web corresponds 
to the length of the paving joints (usually 6 ft.). After the webs are sealed together 
and allowed to cool, they are cut into strips corresponding to the thickness of the 
pavement. 

(4) Armored Bituminized Fabric. Another type of paving joint adapted solely 
for concrete roads, known as an " armored joint," consists of a layer of bituminized 
fabric reinforced on either side by a thin metal plate. The joint may either be 
fiat or corrugated,^ and the upper part constructed with flanges or projections to 
protect the edges of the adjacent concrete sections. 

Another modification is composed of a strip of high fusing-point bituminous 
composition (similar to type 1) reinforced in the centre with a metallic core of wire- 
mesh. ^ Still another consists of a strip of high fusing-point bituminous composi- 
tion protected on the surface with a trough-shaped shell of wire mesh to which in 
turn paper or cloth is cemented fast.^ 

1 U. S. Pat. 105,599 of Jul. 19, 1870 to J. J. Schillinger. 

2 U. S. Pat. 635,170 of Oct. 17, 1899 to T. K. Muir. 
3U. S. Pat. 1,220,766 of Mar. 27, 1917 to W. J. Moeller. 
«U. S. Pat. 1,241,405 of Sep. 25, 1917, to Willis E. Leach. 
8U. S. Pat. 1,078,982 of Nov. 18, 1913 to James Banwell. 
6U. S. Pat. 1,085 275 of Jan. 27, 1914 to W. P. Lonsdale. 



CHAPTER XXV 

BITUMINIZED FABRICS FOR ROOFING, FLOORING, WATER- 
PROOFING, SHEATHING AND INSULATING PURPOSES 

SHEET ROOFINGS 

These are composed of a single layer or a plurality of layers assembled 
together, each composed of a woven or felted fabric, saturated, coated 
or both saturated and coated with bituminous compositions, and in 
special cases reinforced with metal. The finished structure may be sup- 
plied in flat sheets or wound up in rolls of suitable length and width. 
These fabrics and bituminous mixtures may be assembled in innumerable 
combinations.^ 

Felted Fabrics. These are generally formed of rag or asbestos fibres, 
with or without additions, on a machine similar to that used for manu- 
facturing paper. If rags are employed, they are first run through a 
series of revolving knives known as '^ cutters," which shred them into 
small fragments, and then into the " beaters," where they are ground into 
a pulp with water, A beater separates the strands forming the cloth 
into the individual fibres without materially shortening them. A charge 
is beaten one-half to three hours until all the lumps have been broken 
up, whereupon the " pulp " is passed through a '' screen " to remove 
any foreign particles, and then run on the felt machine (Fig. 119), 
where it is formed into a sheet of predetermined thickness. Cylinders 
1 and 2, covered with fine wire cloth, are partly immersed in the tanks 
T-T containing the beaten rag fibres suspended in water. As the 
cylinders revolve, the wire cloth acts as a strainer and picks up a layer 
of fibres, letting the water run to waste. The machine is equipped with 
three endless webs of cloth, 3, 5 and 16. Cloth 5 is first pressed in 
contact with cylinder 1 by the couch roll 11, causing the fibres to adhere 
to the cloth. Cylinder 2 similarly adds a layer of fibres under pressure 

' References. " Ready Roofing Mists and Mysteries," by The Northwestern Lumbermen's Asso- 
ciation, Minneapolis, Minn., 1911; " Roofing Materials Committee Report," Bull. Am. Ry. Eng. 
Assn., 14, 839, 1913; " What is your Market — an Analysis of the Roofing Situation," by C. 
D. Mercer, Curtis Publishing Co., Sept., 1916; " Die Fabrikation der Dachpappe und der Anstrich- 
masse fiir P&ppdacher," Dr. E. Luhmann, 2d Edition, Vienna, 1902; " Wie eine Moderne Teer- 
destillation mit Dachpappenfabrik eingerichtet sein muss," by Willy Peterson-Kinberg, Vienna, 1904. 

386 



BITUMINIZED FABRICS 



387 



of the couch roll 12. The suction box shown 
alongside rollers 11 and 12 draws the surplus 
water from the newly formed sheet of felt, 
which then passes between cloths 3 and 5, 
where it is subjected to gradually increased 
pressure by the rolls 13 and 14. At roll 14, 
the upper cloth 3 returns, while cloth 5 carries 
the sheet of felt to 15, where the felt now 
just strong enough to hold together, leaves 
cloth 5 and passes between pressure rolls 
against the third cloth 16. The felt is now 
carried over a series of steam rolls 8, of which 
modern felt machines are equipped with 55 
to 65. These expel the remaining moisture, 
whereupon the sheet is given a smooth surface 
by the calender rolls 9, and wound into rolls 
at 10, while at 10' the w^ide sheet is slit 
into narrower sheets either 32 or 36 in. 
wide, and automatically rewound into rolls 
by the winders shown at the extreme 
right. 

The Felt Manufacturers' Association of the United 
States recognizes six classes of raw materials for 
making roofing felt, viz.: 

No. 1, Roofing Rags. These constitute soft rags 
carrying a percentage of wool, and include satinet 
garments, men's coats, pants, vests, mixed hnsies, 
seams, women's coats, sacks and cloth skirts. 

No. 2, Roofing Rags. These consist of cotton 
rags, and include large and small cotton rags, 
linings (^^•ithout seam.s), silk rags, rag carpets, print 
rags and stockings. 

No. 3, Gunny Bagging. These include bags and 
sacks free from fertilizer, charcoal, coal, cement, 
chemicals, lime and plaster. 

N^o. 4, Carpets. These include Brussels and hard- 
back carpets. 

No. 5, Roofing Rags. This class includes: (a) tailor 
rags free from all rubbish and paper; (6) tailor 
rags containing not over 10 per cent paper; (c) 
tailor rags containing over 10 per cent but not 
exceeding 50 per cent of paper. 

No. 6, City Dump Rags. Including rags of all 
sorts, and of variable composition. 




-6r\>^ 




388 ASPHALTS AND ALLIED SUBSTANCES 

Miscellaneous Materials. Including canvas, window shades, strings and buckram. ^ 

The following fibres are present in the foregoing classes of materials: 

True rag fibres, including: (1) cotton and linen fibres; (2) wool and silk fibres; 
(3) jute and manila fibres. 

Paper fibers, including: (1) mechanical (i.e., ground) wood pulp; (2) chemical 
wood pulp (sulphite and sulphate). 

No. 1 rags, contain cotton (and linen) also a percentage of wool (and silk) fibres. 

No. 2 rags, contain mostly cotton fibres. 

No. 3 rags, contain cotton, also a percentage of jute and manila fibres. 

No. 4 rags, contain niostly jute and manila fibres. 

No. 5 rags, contain cotton and wool with or without paper fibres. 

No. 6 rags, contain a mixture of all the fibres present in the previous classes. 

The various classes of rags are mixed in suitable proportions in the manufacture 
of roofing felt. Classes 1 and 2 tend to " soften " the felt, and open up its pores 
thereby enabling it to absorb a larger percentage of bituminous saturation. Classes 
3, 4 and 5 tend to " harden " the felt and make it less pHable, less absorbent and 
denser. Class 6 acts variably, depending upon the composition of the rags used. 
It is customary to mix Classes 1 and 2 with Classes 3, 4, 5 and 6 in proportions 
ranging from 5:1 to 1:2, depending upon the nature of the rags available, and 
the quahty of the felt to be manufactured. 

A high grade roofing felt made up approximately of 75-80 per cent " soft " 
rags and 20-25 per cent " hard " rags, will show the following composition on exam- 
ining the finished sheet microscopically (see p. 568): 

Cotton fibres 50-70% 

Wool fibres 10-20% 

Jute and manila fibres 6-15% 

Wood fibres (paper) 1-5% 

Roofing felt is often spoken of as " wool felt," but this term is somewhat of 
a misnomer, since no roofing felt is composed entirely of wool fibres. It is impracti- 
cal to manufacture roofing felt from wool fibres alone, as they are so soft and fluffy 
that they will not form a satisfactory sheet on a felt machine. It is necessary to 
have other fibres present, to produce a strong, compact sheet, not to break on the 
calender rolls or dryers, and to absorb the proper percentage of bituminous satura- 
tion afterwards. 

The durabihty of the various fibres is in exact proportion to their prices. Their 
comparative costs, taking wool as 100, are approximately as follows: 

Wool 100 

Cotton 60 

Jute and manila 44 

Paper (including mechanical and chemical wood fibres) 20 

Wool fibres are most durable and least affected upon contact with moisture or 
the sun's rays. Nature provides wool for covering animals to protect them against 
exposure to the elements. Cotton fibres come next in durabihty. It is significant 
that cotton has always been used for making sail-cloths and covering porches or 

1 The association names the following materials as being unsuited for manufacturing roofing 
felt, viz.: shoe cuttings, felt boots, corsets, suspenders, oil cloth, matting, leather, rubber, rope, 
mackintosh clippings, pasted stock, wood, stones, metals of all kinds, tin cans, glass, bottles, 
ashes, bones, excelsior, etc. 



BITUMINIZED FABRICS C£9 

decks of steamers exposed to the weather. Most of us have observed how much 
more rapidly jute and manila fibres, as for example in the form of burlap bagging, 
will decay, than cotton or wool. Paper fibres require httle comment. Everyone 
knows that a newspaper soon falls to pieces when left out-of-doors in the sun and 
rain, chemical wood fibres (sulphite and sulphate) being somewhat more weather- 
resistant than mechanically ground wood-pulp. Clay is simply used as an adulterant, 
to add weight to the raw felt, without contributing in the least to its longevity. 

The particular kind of fibre present does not influence the strength of the felt, 
which is controlled largely by the following factors: 

(1) The length of the fibres in the felt. This is predetermined by: 

(a) The length of the fibres, as they existed in the rags. 
(6) The extent to which they have been broken up and shortened in the 
beaters. 

(2) The extent to which the rag or paper stock have undergone eremacausis. 
Old rags or papers which have been allowed to rot before being converted into felt 
will produce a weaker sheet than when new rags or paper are emploj^ed. 

(3) The skill displaj^ed in " running " the sheet on the felt machine. 

Many substitute fibres have been suggested for manufacturing roofing felt, 
including the following, viz.: leather fibres,^ cane fibres,- straw fibres,^ asbestos 
fibres in combination with rag fibres,"* cocoa-nut fibres,^ sea grass,^ ground wood 
fibres,^ red-wood, oak and tan barks, ^ moss, peat, etc. 

Waste paper is used most extensively as a substitute for rag stock. It does not 
appreciably affect the strength of the felt, but it tends to increase its density, 
reduce the percentage of bituminous saturation absorbed, make it harder and less 
pliable, and also less weather-resistant. The author has examined samples of roof- 
ing felt containing as much as 65 per cent of paper in admixture with rag stock. 
Straw also decreases the weather resistance of the felt, making it hard and brittle 
and bark reduces its tensile strength. Sea grass does not decrease its strength, 
porosity or brittle ness. 

Mineral substances, such as clay and slag (mineral) " wool " are often used for 
adulterating felt. These may be detected by the ash on ignition. If properly 
made, felt should not yield more than 8 per cent mineral ash. The moisture con- 
tent of the felt as furnished by the manufacturer should not exceed 10 per cent by 
weight.^ 

Rag felt is marketed on the basis of its weight in pounds per 480 sq.ft., known 
as the '' number," ranging from 20 to as high as 90. The '' number " of the felt 
multiplied by 0.225 will give its weight in pounds per 108 sq.ft., and when multi- 
plied by 0.208 will give its weight per 100 sq.ft. High grade rag felt will test 

lU. S. Pats. 40,592 of Nov. 17, 1863 to S. M. Allen; 1,211,837 of Jan. 9, 1917 to C. N. For- 
rest. 

2 U. S. Pat. 88,516 of Mar. 30, 1869 to R. W. Russell. 

3 U. S. Pat. 854,740 of May 28, 1907 to A. G. Hennion. 
4U. S. Pat. 81,641, of Sep. 1, 1868 to H. W. Johns. 

8U. S. Pat. 1,237,000 of Aug. 14, 1917 to Herman von Uffel. 
' «U. S. Pat. 1,226,738 of May 22, 1917 to Herbert Abraham. 

'U. S. Pat. 119,601 of Oct. 3. 1871 and 121,166, Nov. 21, 1871 both to J. K. Griffin; 1,188,495 
of Jun. 27, 1916 to E. J. Schroder. 

8 " The Use of Bark for Paper Specialties," by Otto Kress, J. Ind. Eng. Chcm., 8, 883, 1916. 

9 Determined by distilling a weighed quantity of felt with kerosene, and measuring the volume 
of water rassing over v.'ith the distillate. 



390 ASPHALTS AND ALLIED SUBSTANCES 

approximately 1 mil in thickness, and not less than 0.5 lb. on the Mullen strength 
tester (p. 569), per unit " number." These relations hold approximately constant 
for all weights. 

The following standards have been estabHshed by the Berhn Imperial Testing 
Laboratory.^ 

(1) Rags, fibrous textile waste, and waste paper may be used, but the direct 
addition of wood pulp, straw pulp, peat, sawdust and mineral loading material is 
forbidden. 

(2) The felt must not yield more than 12 per cent of ash. 

(3) The moisture content of the air dry felt should not exceed 12 per cent. 

(4) Felt when immersed in anthracene oil should not absorb less than 120 per 
cent by weight. 

(5) Felt of normal thickness (at least 400 grams per square meter) should have a 
breaking weight ^ (for a strip 15 mm. wide) in the longitudinal direction of at least 
3 kilos. 

So-called " asbestos felt " is sometimes made from asbestos fibres alone, and 
sometimes from a mixture of asbestos and rag fibres. It is marketed on the basis 
of its weight in pounds per 100 sq.ft., and may be manufactured either porous in 
structure, suitable for saturating purposes, or of a dense structure, for attaching to 
the surface of prepared roofings. Samples of asbestos felt for saturating purposes 
examined by the author tested as follows: 

6 lb. asbestos felt 13 mils thick 

8 lb. asbestos felt 17 mils thick 

10 lb. asbestos felt 19 mils thick 

12 lb. asbestos felt 23 m.ils thick 

14 lb. asbestos felt 26 mils thick 

16 lb. asbestos felt 30 mils thick 

40 lb. asbestos felt 70 mils thick 

Woven Fabrics. The woven fabrics ordinarily used for manufactur- 
ing prepared roofings include burlap or hessian (composed of jute fibres) 
and duck (composed of cotton fibres). These are marketed in various 
weights, expressed in arbitrary ways.^ Woven fabrics do not take up 
nearly so large a percentage of bituminous saturation as felted fabrics, 
nor is it possible to impregnate them as uniformly, due to unavoidable 
variations in texture in different portions of the sheet. 

Bituminous Saturating Compositions. Bituminous materials suitable 
for impregnating felted or woven fabrics are usually soft in consistency 
at room temperature, ranging from semi-liquids to semi-solids, with a 

1 J. Marcusson, Mitt. k. Materialpriif., 34, 40, 1916. 

2 The "breaking weight" represents the weight required to break a strip of given width- 

3 Burlaps are designated by the weight in ounces per lineal yard 40 in. wide, and "numbers" 
7f, 8 and 10 are generally employed in manufacturing roofings. " Regular " ducks are designated 
by the weight in ounces per lineal yard 29 in. wide, and "numbers" 6 to 15 are generally used for 
the foregoing purposes. " Enamelling " ducks are designated by the weight in ounces per lineal 
yard of the width in which they happen to be supplied (usually 46, 60 or 72 in.), and "numbers" 
4 to 16 are ordinarily used. " Numbered " ducks are designated in numbers arbitrarily — number 
1 corresponding to a weight of 18 oz. per yard 22 in. wide, and each number greater than 1, to a 
decrease of 1 oz.; numbers 8 (11 oz. per 36 by 22 in.) to 12 (7 oz. per 36 by 22 in.) being 
generally used in manufacturing roofings. 



BITUMINIZED FABRICS 391 

penetration of greater than GO at 77° F. (Test 96), a consistometer hard- 
ness (Test 9c) of less than 15 at 77° F., and a fusing-point by the K. and 
S. method (Test 15a) between 80 and 140° F., or 95 to 160° F. by the 
B. and R. method. 

The following classes of bituminous substances have been used for 
this purpose : 

Group 1. Pure native asphalts, residual asphalts, blown petroleum asphalt, 
sludge asphalt, wurtzihte asphalt, wood-tar pitch, rosin, rosin pitch, bone-tar pitch 
and fatty-acid pitch, used either singly or in various combinations when of the 
required consistency; or else if too hard (and the same appHes also to asphaltites) 
fluxed to grade with one or more of the following, viz.: soft native asphalts, wax 
tailings, residual oil, soft residual asphalts, soft blown petroleum asphalt, soft 
sludge asphalt, soft fatty-acid pitch, animal and vegetable oils or fats, and wool 
grease. 

Group 2. Oil-gas-tar pitch, water-gas-tar pitch, gas-wcrks-coal-tar pitch, coke- 
oven-coal-tar pitch, wood-tar pitch, resin, rosin pitch, bone-tar pitch, and fatty- 
acid pitch, used either singly or in various combinations when of the required 
consistency; or else if too hard, fluxed to grade with one or more of the following, 
viz.: the corresponding Hquid tar previously evaporated to expel the highly volatile 
oils; distillates of high boiling-points derived from the respective tars; wax taihngs; 
soft fatty-acid pitch; animal and vegetable oils or fats; and wool grease. 

The tar and pitch compositions (Group No. 2) are used: (a) for manufacturing 
multiple-layered prepared roofings, and (6) for preparing single-layered tarred felt, 
used for constructing " built-up " roofings (p. 419) and waterproofing membranes 
(p. 428). The Group No. 2 compositions (except fatty-acid pitch) are not recom- 
mended for manufacturing single-layered prepared roofings due to the fact that they 
are insufficiently weather-resisting. On the other hand, the Group No. 1. composi- 
tions on account of their greater weather-resistance n ay be used indiscriminately 
for manufacturing single or multiple layered prepared rccfings, also for asphalt- 
saturated felt used for constructing *' built-up " reefs and waterproofirg irembranes. 

The characteristics of the tar and pitch con positions correspond with the 
figures given for soft coal-tar pitch (see p. 251). Saturating nixtures prepared from 
asphaltic products should comply with the fellowicg characteristics: 

(1) The viscosity at the saturating temperature should be as low as possible 
to accelerate the speed of absorption by the fabric. 

(2) The penetration at 77° F. should be greater than 60 (Test 96), and consist- 
ency (Test 9c) less than 15, otherwise the saturated fabric will be brittle. 

(3) The susceptibihty factor should be as low as possible, and preferably less 
than 30. 

(4) The saturant should be ductile. 

(5) Its fusing-point by the B. and R. method (Test 156) should range from 95 
to 160° F., and preferably between 110 and 150° F. 

(6) It should contain the smallest possible percentage of volatile matter, and 
preferably less than 3 per cent at 500° F. in four hours (Test 16a). 

(7) It should have a flash-point well above the temperature at which it is raised 
during the process of fluxing or while saturating the fabric (at least 50° F.), and 
preferably above 475° F. (Test 17a). 



392 ASPHALTS AND ALLIED SUBSTANCES 

(8) It should contain the largest possible percentage soluble in carbon disulphide, 

and preferably exceeding 97 per cent. 

(9) It should contain a comparatively large percentage soluble in 88° naphtha, 
and preferably exceeding 85 per cent. 

(10) It should be weatherproof (see p. 574). 

Substances formerly used for saturating purposes included rosin and dead oil,* 
pine tar,2 etc., but these are deficient in weather-resisting properties. 

At the present time the materials most commonly employed for saturation pur- 
poses include soft coal-tar pitch, residual oil, soft residual asphalt and soft blown 
petroleum asphalt, of which the respective merits from a weather-resisting point 
of view, have been considered in Chapter XXIII. 

Fire-resisting saturants have recently been suggested, composed of chlorinated 
bituminous bodies, including naphthalene, wax tailings, dead-oil, coal-tar, etc' 
These are used for saturating a single sheet of felted or woven fabric* 

Bituminous Coating and Adhesive Compositions. These may be 
used for surfacing the saturated fabrics (single or multiple layered) and 
also for cementing together two or more layers of fabric (all of which 
may be bituminized, or some bituminized and some untreated) in man- 
ufacturing multiple layered sheets. The coating and adhesive composi- 
tions include the same groups of substances used for the saturant (p. 391), 
but prepared of a harder consistency and usually also of a higher fusing- 
point. The bituminous materials first used for these purposes included 
the fatty-acid pitches,^ native asphalts, sludge asphalts,^ residual 
asphalts, etc. 

The prime requisite of the bituminous coating composition is that it should 
possess maximum weather-resisting properties, since the longevity of the prepared 
roofing depends largely upon the unalterability and integrity of the coating. The 
principles to be followed in making this mixture have already been discussed 
(see p. 338). 

Bituminous coating and cementing compounds should preferably comply with 
the following characteristics: 

(1) The appearance of the surface on aging (Test 3) should be bright, and especially 
where the bituminous coating is to be surfaced with talc or other white mineral 
dusting finish (p. 394). 

(2) The hardness at 77" F. should fall between 10 and 50 on the penetrometer 
(Test 96), and between 15 and 30 on the consistometer (Test 9c). 

1 U. S. Pat. 205,135 of June 18, 1878 to W. H. Rankin. 

2U. S. Pat. 398,337 of Feb. 19, 1889 to W. B. Lupton. 

3.U. S. Pats. 914,223 of Mar. 2, 1909 to J. W. Aylsworth; 914,251 to Carleton Ellis and Karl 
P. McElroy; 1,162,453 of Nov. 30, 1915 to S. R. Church. 

4U. S. Pats. 914,222 of Mar. 2, 1909 to J. W. Aylsworth; 914,300 of Mar. 2, 1909 to Karl P. 
McElroy. 

6 U. S. Pats. 128,599 of Jul. 2, 1872 to W. B. Davies; 423,042 of Mar. 11, 1890 to A. N. Ford; 
English Pat. of 1S67, Sept. 21, No. 2,656 to G. E. Marchisio; 1868, Apr. 23, No. 1,336 to Joseph 
Rogero; 1872, Aug. 29, No. 2,572 to W. R. Lake; 1874, Feb. 4, No. 447 and No. 449 to John 
Macintosh; 1876, Mar. 27, No. 1,309 to Caleb Tayler. 

6Eng. Pat. of 1,888, Apr. 14, No. 5,677 to W. P. Thompson. 



BITUMINIZED FABRICS 393 

(3) The susceptibility factor should be as low as possible, and in the case of 
asphaltic compounds preferably less than 35. 

(4) The ductility should preferably be greater than 1 at 77° F. (Test 106). 

(5) The tensile strength should preferably be greater than 0.5 at 77° F. (Test 11). 

(6) The fusing-point should be such that the composition will not be affected 
by the highest sun temperature to which it may be subjected. It should not be 
lower than 160° F., nor higher than 260° F. by the ball and ring method (Test 
156), the upper limit applying to products having a low susceptibility factor, in- 
cluding blown petroleum asphalts, fluxed asphaltites, etc.; and the lower limit to 
coatings surfaced with fine sand or coarsely ground talc. The corresponding range 
by the K. and S. method (Test 15a) shall be between 145 and 240° F. 

(7) The volatile matter should preferably be less than 2 per cent at 500° F. 
in four hours (Test 16a). 

(8) The flash-point should preferably be above 500° F. (Test 17a). 

(9) The solubihty in carbon disulphide should preferably not be less than 98 
per cent, although this is subject to rr edification where mineral ingredients are 
purposely added for the reasons w^hich follow. 

(10) The larger the percentage of fatty substances (saponifiable) present in the 
mixture, the better will be its weather- resisting properties, other things beirg equal. 

It is sometimes customary to mix mechanically a certain proportion of very 
finely powdered mineral matter with the surface coating while in a molten condi- 
tion, and before it is apphed to the surface of the roofing, for one or more of the 
following reasons: 

(1) To increase the weather-resistance of the bituminous mixture. Opaque 
pigments have been used for this purpose, including graphite,^ lampblack, ^ etc. 
These serve to exclude the actinic rays of the light, which contribute largely to 
the decomposition of bituminous substances (p. 576). 

(2) To impart a color to the bituminous coating. For this purpose, bright 
mineral pigments of various colors are mixed throughout a coating consisting of 
special bituminous compositions having a brown streak (Test 6) or as an alter- 
native showing a transparent to translucent brownish color when viewed on glass 
in a thin layer.^ Bituminous compositions having a black streak, or otherwise 
appearing opaque when viewed on glass in a thin layer, will not answer, for although 
they may initially show the color of the pigment, nevertheless this will disappear 
after a time turning a dull black, since black bituminous mixtures weather to in- 
tensely black substances, due doubtless to the Uberation of free carbon by the 
actinic hght rays. 

(3) To serve as an extender and reduce the cost of the finished product. Many 
substances have been used for this purpose, including finely ground limestone, shale, 
fullers' earth, clay,^ infusorial earth, ^ silica, etc. Another plan consists in apply- 
ing part of the bituminous coating, then the mineral matter such as flake mica, 

» U. S. Pats. 686,191 of Nov. 5, 1901 to W. H. Bache; 853,117 of May 7, 1907 to ClifforJ 
Richardson and C. N. Forrest; German Pat. Appl. 13,156 of Nov. 17, 1904 to Hans Christen; 
Ger. Pat. Appl. A-6,371 of 1907 to E. Kutznit^ki. 

2 U. S. Pat. 727,50"^ of May 5, 1903 to F. J. Warren. 
- 3U. S. Pats. 775,635 and 775,636 of Nov. 22, 1904 to L. C. Rugen and Herbert Abraham; 
Eng. Pat. of 1913, Jun. 18, No. 14,063 to Georg Halle. 

^Eng. Pat. of 1881, Jun. 27, No. 2.815 to A. M. Clark. 

5U. S. Pats. 416,791 of Dec. 10, 1889 to J. I. Livingston and William Griscom; 437,033 of Sep. 
23, 1890 to R. S. Merrell. 



394 ASPHALTS AND ALLIED SUBSTANCES 

and finally the balance of the bituminous coating, thus obtaining an intermediate 
layer of mineral matter.^ 

Where the roofing is to be constructed of mors than one sheet of fabric, very 
fine mineral matter may be mechanically mixed with the bituminous adhesive 
layers for reasons 1 and 3. 

Surfaciiigs of Mineral Matter. Three types of mineral matter are 
distinguished for this purpose, viz.: very fine mineral dust, moderately 
coarse mineral granules and coarse mineral particles. 

The very fine mineral dust is sifted on the surface of the roofing 
usually while still hot, for the purpose of preventing the convolutions of 
the roll from sticking together after it is wound up, or otherwise packed 
for shipment. A certain proportion of it embeds itself in the surface 
coating, but most remains detached, so that it will either shake out of 
the roll, or wash off the roof when applied to the building. The very 
fine dusting finish is therefore applied from a utilitarian standpoint 
rather than for decorative effects. Finely ground talc, silica, mica, 
limestone, infusorial earth, etc., are used for this purpose. 

Moderately coarse mineral granules are purposely embedded in either 
the top or bottom coating, or both, for decorative effects. The mineral 
matter should be practically free from fines, and consist of uniformly 
sized granules, preferably angular. The following materials have been 
used, viz. : sand, coarsely ground talc, coarse flakes of mica,^ also 
colored mineral particles including red or green crushed slate, ^ crushed 
rock of various colors,^ artificially colored sand,^ colored grit,^ baked 
preformed earthy particles of various colors,'^ crushed brick, tile, or 
marble, particles of sand or grit prepared with an oil paint baked on 
superficially, etc.^ 

Coarse mineral particles, either uncolored or colored, are similarly 
embedded in the surface coating for decorative effects, including small 
pebbles, gravel, crushed feldspar or granite,^ crushed seashells,^" granu- 
lated slag,^^ etc. 

Surfacings of Vegetable Matter. The materials in this group include 

lU. S. Pat. 1,187,259 of Jun. 13, 1916 to B. G. Casler. 

« U. S. Pat. 109,486 of Nov. 22, 1870 to Frederick Beck. 

« U. S. Pat. 310,192 of Jan. 6, 1885 to J. T. Edson; 1,007,146 of Oct. 31, 1911 to E. J. Schroder. 

«Ger. Pat. Appl. 10,800 of Mar. 14, 1904 to A. W. Andernach. 

»U. S. Pat. 1,233,501 of July 17, 1917 to J. C. Pelton. 

«U. S. Pat. 1,022,704 of Apr. 9, 1912 to S. G. Wright. 

'U. S. Pat. 1,190,505 of July 11, 1916 to H. E. Boardman; Eng. Pat. of 1912, Apr. 1, No. 
7,872 to A. J. Boult. 

8U. S. Pat. 1,,248,170 of Nov. 27, 1917 to E. J. Schroder. 

"U. S. Pat. 130,376 of Aug. 13, 1872 to Howard Kirk and James Winsmore, Jr. 
loU. S. PatB. 753,982 of Mar. 8, 1904 to S. R. Holland; 1,235,270 of July 31, 1917 to J, B. Wig©. 
»» U. S. Pat, 453,979 of June 9, 1891 to G. S. Lee. 



BITUMINIZED FABRICS 395 

wood flour or sawdust/ granulated cork,^ etc. These are embedded in 
the surface coating while it is hot. The wood flour prevents the con- 
volutions of the rolls from sticking together, and at the same time 
promotes the adhesion between the fabrics and the hot cementing com- 
pound in constructing built-up roofs or waterproofing membranes. 
Cork is used primarily for insulative effects in cold storage work. 
Bituminized fabrics surfaced with cork cannot be used for roofing 
purposes on account of the combustible nature of the cork surfacing. 

Saturating the Fabric. Felted or woven fabrics are impregnated 
with the bituminous saturating mixture by continuously running the 
web through a tank of the latter maintained at a high temperature. 

Attempts have been made, but without success, to saturate the 
felt fibres when they are originally formed into the sheet. ^ Experi- 
ments have recentl}^ been made with an alternative method of inter- 
mingling the fibrous and bituminous constituents in the presence of 
water, by forcing them through a perforated steel plate, and then 
moulding the product in sheet form.'^ 

At the present time the trade recognizes two types of saturated fabric, 
viz.: 

(1) Those saturated with tar products.^ 

(2) Fabrics saturated with asphaltic products,^ including fatty acid 
pitch. '^ 

A modern form of apparatus for producing tar-saturated fabrics is illustrated 
in Fig. 120. The roll of unsaturated fabric is mounted at the left of the illustration. 
The frame or " gallows " in the centre lowers the web into a steam-heated tank 
carrying the hot tar (not shown) by the means of the crank illustrated in the fore- 
ground. After leaving the bath, the saturated sheet passes around two steam- 
heated rolls (shown at the right of the frame work), and thence around the winding 
mechanism shown at the extreme right of the illustration. 

A machine for saturating fabrics with asphalt is shown in Fig. 121. The roll 
of unsaturated fabric is supported at the rear of the illustration, whence it is 
lowered into the tank of the melted asphalt (not shown), by the vertical frame 
operated by the crank shown at the left. After leaving the tank, the saturated sheet 
passes betw^een two steam heated press-rolls one above the other, located in front 
of the frame, and then around five steam-heated rolls mounted in tw^o tiers, three on 
top and two below. These drive the excess of asphalt into the sheet, causing the 

1 U. S. Pat. 1,203,403 Oi Oct. 3^, 1913 to Mathias Poulson. 

JU. S. Pat. 674,219 of May 14, 1901 to J. A. Scharwath. 

>U. S. Pat. 103,199 of May 17, 1870 to Samuel Kingan; Ger. Pat. 216,753 of Sep. 6, 1906 to 
Julius Kathe. 

^U. S. Pat. 1,204,632 of Nov. 14, 1916 to J. C. W^oodley and R. P. Perry. 

5U. S. Pats. 103,536 of May 31. 1870 to T. R. Abbott; 111,611 of Feb. 7, 1871 to J. M. Cobb; 
119.059 of Sept. 18, 1871 to H. N. Stiu:8on; 230.148 of July 20, 1880 to G. S. Page; 825,744 
of July 10, 1846 to A. F.. Millington. 

6 British Pat. of 1876. May 21. No. 2.295, to J. S. Norrie; U. S. Pats. 820.694 of May 15, 
1906, to L. A. Bond; 876,008 and 876,010 of Jan. 7, 1908 to F. C. Overbury. 

^Ger. Pat. 122,893, May 5, 1899, to A. W. Andernach. 



396 



ASPHALTS AND ALLIED SUBSTANCES 




Courtesy of The Moore & White Co. 
Fig. 120.— Tar Saturator. 




Courtesy of The Moore & White Co. 

Fig. 12L — Asphalt Saturator. 



BITUMINIZED FABRICS 



397 



saturated fabric to leave the machine perfectly " dry." It is then wound in large 
rolls on the automatic winder shown in the foreground. 

The tanks in both the tar and asphalt saturators may be heated either by steam 
or direct fire. The former is ordinarily used because of the safety and ease of con- 
trol. Tar products are usually maintained at 200-270° F., and asphaltic products 
at 225-400° F. In the types of machines illustrated, the fabric may be saturated 
at a speed of 330-350 lineal feet per minute. The weight of saturation absorbed 
by the fabric is controlled by the depth to which the web is immersed in the tar 
or asphalt, which in turn is regulated by raising or lowering the frame. The 
surface of the web in contact with the saturant varies from 10 to 30 lineal feet. 

The following figures will give some idea of the percentages of saturating mate- 
rials taken up by the fabric, based on its raw weight: 

Felt will absorb 115-180 per cent of soft coal-tar pitch, or 100-165 per cent by 
weight of asphalt. 

Burlap will absorb 90-125 per cent of soft coal-tar pitch, or 75-100 per cent by 
weight of asphalt. 

The larger the percentage of any given saturant absorbed by the felted or woven 
fabric, consistent wdth the formation of a " dry " surface, the more durably will 
the fibres be water-proofed and weather-proofed. If the felt is undersaturated, the 
finished sheet wiU he porous and absorb moisture in service. On the other hand, 
if the sheet is oversaturated, a part of the saturant will remain on the surface 
and cause the convolutions of the roU to stick together. The best practice consists 
in running a sheet so that it wiU show " wet spots " as it leaves the bath of satu- 
rant, which, however, will become absorbed when it cools to atmospheric tempera- 
ture. The absorption may be assisted by preventing the surface cooling too quickly, 
so that the natural contraction of the saturant will have an opportunity of drawing 
in the " wet " spots by capillarity. 

It is customary to market tar and asphalt saturated felts in rolls of the follow- 
ing dimensions and weights: 



Size of Roll. 



Wcigl t f er 100 Sq.ft. 



Weight per lOS Sq.ft 



"Slaters' Felt" (Tarred): 

30 lb. per 500 sq.ft. . . 

33 lb. per 500 sq.ft. .. 

40 lb. per 500 sq.ft. .. 
Tarred felt: 

50 lb. per 432 sq.ft . . . 

60 lb. per 500 sq.ft. . . 

40 lb. per 324 sq.ft. . . 

55 lb. per 432 sq.ft. . . 
60 lb. per 432 sq.ft . . . 
48i lb. per 324 sq.ft. . 
60 lb. per 400 sq.ft. . . 
43 lb. per 216 sq.ft. . . 
60 lb. per 250 sq.ft . . . 

Asphalt felt: 

4:4: lb. per 432 sq.ft. . . 

60 lb. per 500 sq.ft . . . 

56 lb. per 400 sq.ft . . . 
48i lb. per 324 sq.ft... 
43 lb. per 216 sq.ft. . . 



Pounds. 
6.0 
6.6 
8.0 

11.5 

12.0 

12.3 

12.75 

14.0 

15.0 

15.0 

20.0 

24.0 

10,2 
12.0 
14.0 
15.0 
20.0 



Fount's. 
C.5 
7.1 
8.65 

12.5 

13.0 

13.3 

13.75 

15.0 

16.2 

16.2 

21.4 

25.9 

11.0 
13.0 
15.0 
16.2 
21.4 



398 ASPHALTS AND ALLIED SUBSTANCES 

Fabrics saturated with tar or asphaltic products are used for the following 
purposes: 

(1) As an intermediate product in the manufacture of " prepared roofings " 
and composition shingles. 

(2) In the manufacture of bituminized floor coverings. 

(3) For constructing " built-up " roofs. 

(4) For constructing waterproofing membranes. 

(5) For bituminous expansion joints. 

" Prepared roofings " are distinguished from " saturated fabrics " by being com- 
posed of: (1) Single-layered fabrics coated alone, or both saturated and coated with 
bituminous compositions; (2) laminated (multiple layered) bituminated fabrics 
having at least one of the layers saturated, the fabric being either unsurfaced, or 
surfaced on one side, or else surfaced on both sides with bituminous compositions. 
In the next succeeding section, we will consider prepared roofings composed of a 
single layer of fabric. 

Single-layered Prepared Roofings. In the early days of the indus- 
try it was customary merely to surface a felted or woven fabric with 
bituminous substances.^ The next step in the development of the indus- 
try consisted in both saturating and coating a single web of fabric with 
bituminous mixtures, and surfacing with talc, sand, powdered limestone 
or gravel.^ 

Most of the prepared roofings manufactured to-day are made up 
of a single layer of " roofing felt " saturated with bituminous ingre- 
dients of relatively soft consistency, and surfaced on both sides with 

1 U. S. Pats. 3,598 of May 25, 1844, to Edouard Deutsch, describing the use of asphalt com- 
bined with fats or oils for coating paper or cloth; 17,851 of July 21, 1857 to J. B. War.ds, describ- 
ing cotton cloth coated with coal tar and fatty-acid pitch and surfaced with sand; 80,207 of July 
21, 1868 to Alfred Paraf, coating woven cloth with a mixture of grahamite and vegetable oil; 
151,683 of June 9, 1874 to Elias Burnham, coating felt with coal-tar pitch and sanding the surface; 
187,748 of Feb. 27, 1877 to J. C. Cheatham, coating cloth with a mixture of coal tar, lime and sul- 
phur and surfacing with gravel; 278,481 of May 29, 1883, to S. M. Allen, coating felt or paper 
with a mixture of asphalt and pulped fibres; Eng. Pat. of 1885, Oct. 31, No. 13,140 to J. E. A. 
Pierret, coating felt or burlap with a mixture of sludge asphalt, native asphalt, rosin and earthy 
matter and surfacing with sand; 1888, Mar. 5, No. 3,354 to Thomas Thomson, coating cloth with 
a mixture of fatty-acid pitch, vegetable oil, chalk, fibrous matter and a colored pigment; 1889, 
May 27, No. 8,795 to A. N. Ford, coating woven fabrics with a mixture of fattj'-acid pitch, lin- 
seed oil, soap and petroleum. 

2 U. S. Pats. 93,859 of Aug. 17, 1869 to J. M. Cobb, felt saturated and coated with tar and sur- 
faced with sand or gravel; 179,828, 179,829, and 179,830 of July 11, 1876 to C. M. Warren, also 
180,081 of July 18, 1876, and 191,208 of May 22, 1877 to C. M. Warren, felt or paper saturated and 
coated with mixtures of native asphalt, residual asphalt and fatty-acid pitch; 282,139 of July 31, 1883 
to Welcome White, felt saturated with tar and coated on one side with a mixture of coal tar, asbestos 
and soapstone; 300,946 of June 24, 1884 to Philip Carey, felt composed of wood pulp, asbestos 
and clay saturated and coated with asphalt; 345,399 of July 13, 1886 to C. M. Warren, felt satur- 
ated and coated with a mixture of native asphalt, sludge asphalt and fatty-acid pitch; 348,996 
of Sept. 14, 1886 to T. J. Pearce. and W. M. Eeardsley, saturating and coating a felted or woven 
fabric with residual asphalt; 358,502 of Mar. 1, 1887 to C. W. Swan, a woven fabric saturated and 
coated with residual asphalt and surfaced with liniestore; Eng. Pat. of 1879, Jime 27, No. 2,596 
to W. B. Ritchie, felt saturated and coated with a biti n inoi s ronpcsition; 1897, Apr. 1, No. 
8,343, to J. D. Black well, saturating and coating clcth with fatty-acid ritch; Ger. Pat. 92,308 of 
Aug. 12, 1895 to A. W. Andernach, felt saturated with coal tar, coated with a bituminous mixture 
containing sulphur, and surfaced with sand. 



BITUMINIZED FABRICS 399 

a harder bituminous composition. They are marketed in roll form, 
either 36 in. or 32 in. wide, measuring 108 sq.ft. in area, knov>^n com- 
mercially as a " square," which is sufficient to cover 100 sq.ft. of roof 
surface, allowing for 2-in. laps at the joints. Prepared roofings are 
marketed in several weights known to the trade as " plies." The term 
" ply," however, is a misnomer, as it does not, as one would suppose, 
refer to the layers of fabric forming the roofing, but is used to desig- 
nate the weight of the sheet consisting of a single layer. It is customary 
to manufacture a so-called " 1-ply " roofing to weigh 35 lb. gross per 
square, including the paper wrapper and heads, together with sufficient 
nails and Hquid lap-cement for laying, packed in the core of the roll. 
The net weight of the roofing runs 2 to 4 lb. per square less than its 
gross weight. " 2-ply " roofing weighs 45 lb. gross per square, and 
" 3-ply " 55 lb. Heavier weights are also manufactured, especially in the 
case of roofings surfaced with moderately coarse to coarse mineral 
matter, which are often made to weigh 100 lb. per square or over. 
Unfortunately, no standard practice is followed in manufacturing the 
heavier weights, each manufacturer being guided by his own views. 

The surface may be manufactured smooth, or it may have a 
" veined " appearance as illustrated in Fig. 122. In either event, it is 
customary to sprinkle a " dusting finish " of finely powdered mineral 
matter on the surfaces (p. 394) to prevent the convolutions of the roll 
sticking together during transit or in storage. It is desirable to apply 
the dusting finish while both coatings are hot, so that as much as pos- 
sible will embed itself in the surfaces and will neither blow away nor 
be washed off the roofing by the first rainstorm, after being laid on a 
building. Not more than 3 lb. per square is necessary for this purpose.^ 
In other cases, either one or both surface coatings may be adorned with 
moderately coarse particles of mineral matter (p. 400), including 
coarsely ground talc, of which 8 to 15 lb. are applied per square to 
both sides of the sheet (Fig. 123); small rounded grains of sand, of 
which 10 to 20 lb. per square are used, including both sides of the 
roofing (Fig. 124) ; and angular particles of crushed slate^ or greenstone, 

' Granularmetric analyses of the talc, used as '* dusting finish " will show from 5 to 25 per 

cent of particles passing an 80-, but retained on a 100-mesh sieve, the former applying to finely 

ground talcs and the latter to coarsely bolted products. 

* Crushed elate used by the leading manufacturers in this country tests as follows: 

Passing 60 but retained on 80-mesh sieve 0- 1% 

Passing 40 but retained on eO-meeh sieve 1-10% 

Passing 20 but retained on 40-me8h sieve 20-65% 

Passing 10 but retained on 20-me8h sieve 35-70% 

Passing 8 but retained on 10-mesh sieve 0-1% 

Specifications require that less than 2 per cent shall pass a 40- or an 8-mesh sieve, less than 33 

per cent shall pass a 20-, and more than 50 per cent pass a lO-mesh sieve. 



400 



ASPHALT AND ALLIED SUBSTANCES 







Fig. 122. — ^Prepared Roofing Finished in 
a Veined Surface. 



Fig. 124. — Prepared Roofing Finished 
with Fine Sand. 




Fig. 123. — Prepared Roofing Finished 
with Coarse Talc. 










Fig. 125. — Prepared Roofing Finished 
with Crushed Slate. 




Fig. 126. — Prepared Roofing Finished 
with Crushed Feldspar. 



Fig. 127. — Prepared Roofing Finished 
with Pebbles. 



BITUMINIZED FABRICS 401 

of a reddish or greenish color respectively (Fig. 125), of which 25. to 35 
lb. per square are affixed to one side of the sheet. It is customar}^ to 
embed the coarsely ground talc in both coatings, the rounded grains 
of sand in either one or both coatings, and the angular particles of 
slate or greenstone is one coating only. The last, known as '' slate- 
sti'rfaced roofing," is usually manufactured from a No. 50 to No. 55 
dry felt, so that the finished weight including nails and cement will 
range between 80 and 85 lb. per square. 

One-ply roofing is variously manufactured from No. 30 to No. 45 dry felt, 
two-ply from No. 40 to No. 60 and three-ply from No. 50 to No. 75. Where the 
light weight dry felt is used in manufacturing any particular ply, a corresponding 
larger proportion of coating must be applied to bring the weight of the finished 
roofing to 35, 45 or 55 lb. gross, whichever the case may be. • The weight of dry 
felt used will average No. 35, No. 50 and No. 65 for the one-, two- and three-ply 
respectively. 

In other cases coarse particles of mineral matter are embedded in the upper 
surface only, including crushed feldspar, of whi(;h 30-40 lb. are used per square 
(Fig. 126), or even fairly large pebbles, of which 40-65 lb. are used per square (Fig. 
127). 

The weights of bituminous coating (unfilled or filled) appHed per square, exclu- 
sive of the mineral surfacing, range as follows: 

1-ply (35 lb.) 6 to 15 lb. (both sides) 

2-ply (45 lb.) • 7 to 20 lb. (both sides) 

3-ply (55 lb.) ■ 8 to 25 lb. (both sides) 

Slate surfaced (80 lb.) 15 to 25 lb. (one side) 

The thicknesses of the finished roofings vary between the following Umits-: 

Surfaced with talc 1-ply (35 lb.) 50 to 60 mils 

Surfaced with talc 2-ply (45. lb.) . 65 to .80. mils 

Surfaced with talc 3-ply (55" lb.) 80 to 100 mils 

Surfaced with fine sand 1-ply (35 lb.) 45 to 50 mils 

Surfaced with fine sand 2-ply (45 lb.) 60 to 65 mils 

Surfaced with fine sand 3-ply (55 lb.) 75 to 80 mils ' 

Surfaced with fine sand ; X-ply (65 lb;) 90 to 100 mils 

Surfaced wdth fine sand XX-ply (75 lb.) 105 to 115 mils 

Surfaced with crushed slate (80 lb.) 120 to 145 mils 

The composition of typical single-layered prepared roofings is shown in 
Table XXXII. 

Cross-sections of the principal forms of single-layered prepared roofing are sho'\\Ti 
in A, B, and C, Fig. 199. 

A single sheet of woven fabric such as duck, surfaced on one side wdth a bitu- 
minous mixture dusted with powdered talc or mica, is largely used at the present 
time for covering steamboat decks or porch roofs where subjected to foot traffic. 
The material is laid with the bituminous side down, whereupon the unsurfaced duck 
is painted mth several coats of a colored linseed-oil-pigment paint. A single sheet 
of woven fabric saturated with a soft bituminous composition, coated on both sides 



402 



ASPHALTS AND ALLIED SUBSTANCES 



TABLE 





Type A. 


Tyfe a. 


Roofing 36 Inches Wide. 


Smooth Surlaced 
(Unfilled Coatmgs). 


Smooth Surfaced 
(Filled Coatings). 




1-pIy. 


2-ply. 


3-ply. 


1-ply. 


2-ply. 


3-ply. 




Lb. 

1.5 
0.3 
0.2 


% 

4.7 
1.0 
O.C 


Lb. 

1.8 
0.4 
0.3 


% 

4.3 
1.0 
0.7 


Lb. 

2.1 
0.5 
0.4 


% 

4.0 
1.0 
0.8 


Lb. 

1.5 
0.3 
0.2 


% 

4.7 
1.0 
0.6 


Lb. 

1.8 
0.4 
O.S 


% 

4.3 
1.0 
0.7 


Lb. 

2.1 
0.5 
0.4 


% 


Mineral Matter 
Fine dusting finish detached (top 

and bottom) 

Fine dusting finish embedded in top 

coating 

Fine dusting finish embedded in 


4.0 
1.0 

8 


SanH prnhftHrlfrl in inn pnntinc 












. . . . 


















Crushed slate embedded in top coat- 








































3.6 
2.5 


11.2 

7.8 


4.1 

2.8 


9.7 
6.7 


5.0 
3.3 


9 6 


TTillpr nrlmivftH ivit.h bn+tnm f.nntinff 














6 3 


Filler admixed with cementing layer. 
Bituminous Matter 








.... 








4.7 
3.1 


14.7 
9.7 


5.1 
3.4 


12.1 
8.1 


5.5 
3.6 


10.6 
6.9 


5.4 
3.6 


16.9 
11.2 


6.2 
4.2 


14.8 
10.0 


7.4 
4.9 


14 ? 




9.5 






Saturatine the felt 


12.1 
10.1 


37.8 
31.5 


17.5 
13.5 


41.7 
32.1 


23.3 
16.6 


44.8 
31.9 


8.1 
6.8 


25.3 
21.3 




12.1 

10.1 


28.8 
24.0 


16.0 
12.4 


30 8 


Fibrous Matter 


23 8 


TJrv Riirlnn 






32 

1.6 
1.4 

35 


100 


42 

1.6 
1.4 

45 


100 


32 

1.6 
1.4 

55 


100 


32 

1.6 
1.4 

35 


100 


12 

1.6 
1.4 

45 


100 


52 

1.6 
1.4 

55 




Total per square (108 sq.ft.) 


100 


Fixtures 
Nails, including cardboard container. 








Total per square (108 sq.ft.) 





with a mixture of harder consistency and surfaced with powdered talc or mica, is 
being used largely for roofing railroad passenger cars and locomotive cabs. This 
is manufactured from ^'numbered" ducks weighing 1L46 and 14.73 ounces per square 
yard, the finished weights being 2.15 and 2.30 lb. per square yard respectively. 

In manufacturing single-layered prepared roofings, the sheet of felted or woven 
fabric is first saturated by passing it through a bath of the melted bituminous 
saturation. The saturated sheet may then be coated immediately with a bituminous 
composition and while it is still hot, or else it may be wound into large rolls, 
allowed to cool and coated later. Both methods are used at present, the latter 



BITUMINIZED FABRICS 



403 



XXXII 



Type B. 


Type C. 


Type C. 


Type D. 


Type E. 


Type F. 


Sanded Top and Bottom. 


Sanded Bottom Only. 


Slate 
Surfaced. 


Burlap 
Backed. 


Double 
Layered. 


Builap 
Cei.tre. 


1-ply. 


2-ply. 


3-piy. 


1-ply. 


2-ply. 


3-ply. 


.... 








Lb. 


% 


Lb. 


% 


Lb. 


% 


Lb. 


% 


Lb. 


% 


Lb. 


% 


Lb. 


% 


Lb. 


% 


Lb. 


% 


Lb. 


% 














0.7 
0.3 


2 2 
0.9 


0.9 
0.4 


2.1 
1.0 


1.1 
0.5 


2.1 
0.95 






1.8 
0.4 
0.3 


4.3 
1.0 
0.7 


1.6 
0.4 
0.4 


3.1 
0.8 

0.8 












































5 


15.6 
15.6 


6.0 
6.0 


14.3 
14.3 


7.5 
7.5 


14.45 
14.45 


















7.5 
7.5 


10 4 


^ 


5.C 


15.6 


6.C 


14.3 


7.5 


14.45 






. . 








10 4 




28.0 
8.3 


36.3 
10.8 




2.3 
4.3 


5.5 
10.2 


2.1 
2.1 
2.4 

4.2 
4.2 
4.8 
,8.1 
<8.1 

j6.8 
(6.8 


4.0 
4.0 
4.6 

8.1 

8.1 

9.3 

15.5 

15.5 

13.1 
13.1 
















2.0 
1.7 


6.3 
5.3 


2.3 
1.9 


5.5 
4.5 


2.6 
2.2 


5.0 
4.2 






































4.2 


13.1 
9.1 


4.7 
3.1 


11.2 
7.4 


5.1 
3.5 


9.8 
6.7 


4.C 
3.4 


12.5 
10.6 


4.5 
3.8 


10.7 
9.1 


5.2 
4.5 


10.0 

8.7 


12.3 


16.0 


4.2 
8.7 


10.0 
20.7 


5.8 
5.8 
10.5 
8.1 
8.1 

6.8 
6.8 
5.1 

72 


8.1 
8 1 








14 5 


8.1 
6.8 


25.3 
21.3 


12.1 
10.1 


28.8 
24.0 


16.0 
12.4 


30.8 
23.8 


8.1 
6.8 


25.3 
21.3 


12.1 
10.1 


28.8 
24.0 


16.0 
12.4 


30.8 
23.8 


16.0 
12.4 


20.8 
16.1 


8.1 

6.8 
5.1 


19.3 

16.2 
12.1 


11.2 
11.2 

9.5 
9.5 

7 1 




































32 


100 


42 


100 


52 


100 


32 


100 


42 


100 


52 


100 


77 


100 


42 


100 


52 


100 


.00 


1.6 
1.4 




1.6 
1.4 




1.6 
1.4 




1.6 
1.4 




1.6 
1.4 


.... 


1.6 
1.4 




1.6 
1.4 




1.6 
1.4 




1.6 
1.4 




1.6 
1.4 


.... 


35 


45 




55 




35 




45 




55 




80 




45 




35 




75 





being known as the intermittent and the former as the continuous process. Each 
is claimed to have its particular advantages. The author is inclined to favor the 
continuous process, since the coating is applied directly to the hot sheet, which 
enables the saturating compound on cooHng and contracting to draw the hot and 
plastic surface coating into the sheet, forming a " key " between the coating and the 
fabric, and producing a denser sheet of roofing. For this reason, roofings made by 
the continuous process do not measure as thick for a given weight, although to 
counterbalance this, they are less porous, and consequently are less apt to absorb 
moisture. 



404 ASPHALTS AND ALLIED SUBSTANCES 

The intermittent type of roofing machine is constructed in two units, operating 
independently. The felt is first saturated and wound into large rolls on an asphalt 
saturator as illustrated in Fig. 121, and subsequently run through the coating 
machine shown in Fig. 128. The roll of saturated felt, 1, is passed through steam- 
heated coating rolls 2 and 3, which distribute the melted coating composition fed 
from an overhead storage tank (not shown). Pd'ineral surfaeings may be applied 
by the mechanically actuated hopper 4. The sheet is then drawn through the 
'' pull-rolls " 5, after which it is cooled by an automatic looping device, which 
catches the sheet at 6 and' carries it along towards the winder and cutter 8, allow- 
ing the loops to accumulate at 7. The cooling loops 7 will accommodate 25-50 
squares of roofing and thus enable the coating operation to continue uninterruptedly, 
even though the winder and cutter may temporarily cease operating, as for example, 
when a finished roll of roofing is removed from the winder bar at 8. 

The simplest form of machine for manufacturing roofing continuously is illus- 
trated in Fig. 129. A roll of raw felt is shown on the " unwinder " at the left of 
the figure. The sheet then passes through the saturator, zigzagging tack and forth 
several times to present a large area to the compound and increase the time of 
contact. From the saturator the web passes around the steam-heated " saturating 
rolls " which " drive in " the saturant and remove the excess, so that the surface 
of the sheet will appear " dry," when the top and bottom coatings are appUed 
by the steam-heated coating rolls. The melted coating mixture is flowed on the 
upper side of the sheet where it is spread uniformly by the upper roll and the excess 
allowed to flow into a small tank underneath, where it is picked up by the lower 
coating roll and spread on the under side of the sheet. The mineral surfacing is 
applied when the sheet reaches the coolers by the contrivance shown in Fig. 130, 
the sheet first passing underneath hopper A where particles of talc, sand or mode- 
rately fine granular matter are evenly distributed on the upper surface, and then 
around the water-cooled roll A which firmly presses the mineral matter into the 
hot and soft coating. Hopper B applies the particles to the underside of the sheet, 
and the water-cooled roll B, embeds them into the bottom coating. The " coolers " 
consist of large hollow water-cooled drums. The " puU " rolls supply the necessary 
tension and are provided with a measuring device, which enables the winder shown 
at the right of the figure to roll up and cut the finished roofing into small units 
of suitable lengths. The details of the winding mechanism are depicted in 
Fig. 131. 

Another machine for manufacturing roofing continuously, embodying some of the 
features of both machines previously described, is shown in Fig. 132. The sheet 
travels from right to left, first through a " saturator," consisting of a deep tank 
heated by steam or direct fire, and then around a stationary air-cooled looping 
system. The surface coatings are next applied to both sides of the sheet, and while 
still hot, mineral particles are sifted on the upper surface from the so-called " slate 
feeder." The sheet then travels around eight water-cooled drums, of which the 
first two serve as press-rolls to firmly embed the particles in the coating. After 
this, the web is carried along by a movable looping device similar to that shown 
in Fig. 128, which serves to cool and store the finished sheet until it can be handled 
by the draw-rolls, winder and cutter shown at the extreme right of the illustration. 
One method consists in saturating and coating a sheet of double width and then 
slitting it longitudinally into two sheets of the desired width. ^ 

1 U. S. Pats. 876,008 and 876,010 of Jan. 7, 1908 to F. C. Overbury. 



BITUMINIZED FABRICS 



405 




406 



ASPHALTS AND ALLIED SUBSTANCES 




mnnSmAmmmmmmmmMmmmmm 



Courtesy of Guyton & Cumfer Mfg. Co. 
Fig. 130. — Device for Applying Mineral Particles to the Surface of Prepared Roofing 




Fig. 131. — Winding Mechanism. 



BITUMINIZED FABRICS 



407 



Very often prepared roofings surfaced with 
finely powdered mineral matter, such as talc 
or limestone, turn yellow on aging indoors. 
This discoloration is due to the use of: 

(1) Bituminous coating or saturating 
mixtures containing a large proportion of 
volatile matter. 

(2) Coating compositions which do not 
blend thoroughly. 

(3) Coatings containing a large propor- 
tion of " greasy " or oily constituents which 
impart a dull surface to the specimen on 
aging indoors one week (Test 3). 

This yellow discoloration not only detracts 
from the appearance of the roofing and inter- 
feres with its sale, but indicates that improper 
mixtures have been used in its manufacture. 

The function of the coating is to seal 
in the saturation, protect it from oxidation 
and volatilization, and exclude moisture from 
the fabric fibres. The coating should weather 
away gradually and uniformly. As soon as 
the coating disappears through weathering 
or attrition of the elements, the fabric will 
commence to rot and weaken, until it tears 
during the first heavy wind, and this will 
terminate the life of the roofing. 

A properly laid prepared roofing will no 
longer fulfil its function as a result of: 

(1) Local perforations due to the coating 
compound failing in spots, the seams opening 
up on account of the lap-cement being faulty, 
hard lumps or particles in the felt, rusting 
away of the nails, the bituminous matter being 
extracted from the felt by rosin or turpentine 
in the roof boards, the fabric drying out or 
othe revise becoming brittle and cracking, the 
roof being subjected to undue external vio- 
lence such as a hailstorm, rough walking 
upon it, dragging heavy articles over it, 
objects falling upon it, etc. 

(2) The fabric weakening to such an extent 
that it is torn and rendered unserviceable 
by the first heavy windstorm. As long as the 
weather coating remains intact, this will not 
occur, but just as soon as it wears thin or dis- 
appears, moisture will find its way into the 
fabric and rot its fibres, so that the roof is 
soon doomed unless it is repainted (p. 470). 



^2z~^' 



./ 



^^^^•^ 






7^ 



f^l 



1^ 

C p4 






^ 



bC 






u 






408 ASPHALTS AND ALLIED SUBSTANCES 

(3) Trouble caused by the underlying roof boards, due to shrinkage, cracking, 
splitting or rotting, which would subject the roofing to excessive strains, and either 
rip it from the seams or tear the sheets. 

Most manufacturers recommend that prepared roofings be coated from time to 
time with a bituminous paint (p. 470) to renew the weather-coating as it wears 
away. This procedure is applicable to smooth-surfaced roofings, or ones surfaced 
with very fine sand or grit. Slate-surfaced roofings or roofings coated with gravel 
or crushed rock are not amenable to painting, due to the interference of the coarse 
mineral particles. With proper care and repainting at intervals, a properly manu- 
factured single layered 3-ply smooth surfaced prepared roofing will remain service- 
able for 20 years. Some manufacturers guarantee the 1-ply roofing to last five years 
without painting, 2-ply from five to ten years with one painting, and the 3-ply 
from ten to twenty years with two or more paintings. As in other industries, 
it is generally true that the smaller and less responsible the manufacturer, the more 
extravagant the guarantee offered. In recent years, guarantees have been very much 
overdone by certain prepared roofing manufacturers, and as a result the public has 
grown wary, but is fortunately beginning to pay more attention to the manufac- 
turer's reputation and to the record of the particular brand of roofing, which after 
all afford much better assurance than a " guarantee." 

Laminated Prepared Roof ngs. These consist of two or more layers 
of bituminized felted fabric, composed of vegetable or animal fibres/ 
two or more layers of bituminized woven fabric composed of animal or 
vegetable fibres; ^ two or more layers of bituminized felted and woven 
fabric composed of animal or vegetable fibres; ^ combinations of plain 
or saturated asbestos felt with bituminized woven or felted fabrics 
composed of vegetable and animal fibres.^ 

1 U. S. Pats. 44,220 of Sept. 13, 1864, and reitsue 4,862 of Apr. 9, 1872 to Alfred Robinson; 
48,311 of Jun. 20, 1865, and 75,197 of Mar. 3, 1868 to Alfred Robinson; 202,902 of Apr. 23, 1878 to 
C. M. Warren; 211,669 of Jan. 28, 1879 to W. H. Rankin, 237,158 of Feb. 1, 1881 to R. A. Ben- 
dall; 256,368 of Apr. 11, 1882 to G. H. Poschel; 278,278 of May 22, 1883 to Augustine Sackett; 
291,600 of Jan. 8, 1884 to Josiah Jowitt; 312,451 of Feb. 17, 1885 to Michael Ehret, Jr.; 318,910 of 
May 26, 1885 to Josiah Jowitt; 341,043 of May 4, 1886 to Tobias New; 351,948 of Nov. 2, 1886 
to C. M. Warren; 362,202 of May 3, 1887 to Philip Carey; 418,569 of Dec. 31, 1889 to H. W. 
Johns; 427,174 of May 6, 1890 to M. C. Kerbaugh; 429,885 of June 10, 1890 to W. H. H. Childs; 
455,000 of June 30, 1891 to M. C. Kerbaugh; 674,219 of IMay 14, 1901 to J. A. Scharwath; 851,331 
of Apr. 23. 1907 to H. R. Wardell; Eng. Pat. of 1873, Sept. 26, No. 3,147 to J. A.Turner; Ger. 
Pat. 121,436 of May 6, 1899 to A. W. Andernach. 

2 Eng. Pat. of 1888, Sep. 28, No. 13,971 to Donald Nicoll; U. S. Pat. 1,248,909 of Dec. 4, 
1917 to H. B. Pullar. 

a U. S. Pats. 125,574 of Apr. 9, 1872 to H. W. Johrs: 150,636 of May 5, 1874 to J. A. Turner; 
278,722 of June 5, 1883 and 293,491 of Feb. 12, 1884, also 304,744 of Sept. 9, 1884 all to H. M. Miner; 
385,057 of June 26, 1888 to Alexander Jones; 453,979 of June 9, 1891, and 460,668 of Jan. 31, 1893 
both to G. S. Lee; 624,976 of May 16, 1899 to R. J. Redick; 636,022 of Oct. 31, 1899 to G. D. 
Crabbs and W. H. Pendery; 753,982 of Mar. 8, 1904 to S. R. Holland; 775,968 of Nov. 29, 1904 to 
August Gross; 813,336 of Feb. 20, 1896 to H. R. Wardell; 820,470 of May 15, 1906 to R. W. 
Bird; 845,414 of Feb. 26, 1907 to Samuel Herbert; Eng. Pat. of 1888, Apr. 14, No. 6,577 to W. P. 
Thompson; 1893, Oct. 14, No. 17,003 to Emile Pierret. 

*U. S. Pats. 333,138 of Dec. 29, 1885 to Francis Line; 418,519 of Dec. 31, 1889 to H. W. 
Johns; 690,526 of Jan. 7, 1902 to F. S. Miller and W. B. Davenport; 817,619 of Apr. 10, 1906 
to G. F. Bishopric; 1,220,966 of Mar. 27, 1917 to O. R. Emigh; Ger. Pat. 141,760 of May 22, 1901 
to Maurice Coutellier. 



BITUMINIZED FABRICS 409 

The fabrics may be combined in innumerable ways, and in as many 
layers as desired, but generally with five as the maximum. At the 
present time the most popular forms of multiple-layered prepared roof- 
ings include the following: 

(1) Two or three layers of tarred felt cemented together with coal- 
tar pitch. 

(2) Asphalt-saturated felt fastened with an asphaltic adhesive to an 
asphalt- saturated burlap, and surfaced top and bottom with an asphaltic 
composition. 

(3) Burlap embedded in an asphaltic adhesive between two layers of 
asphalt-saturated felt, and surfaced top and bottom with an asphaltic 
composition. 

(4) Untreated cotton duck fastened with an asphaltic adhesive to an 
asphalt-saturated and coated felt. This form is intended for use as a 
decking or porch covering, to have its upper surface painted with an oil 
paint, as previously described. 

(5) Two or more layers of asphalt-saturated asbestos, fastened 
together with an asphaltic adhesive, and in some cases surfaced either 
with a sheet of unsaturated asbestos felt, or with an asphaltic coating 
composition. 

(6) An asphalt-saturated fabric, either woven or felted, fastened with 
an asphaltic adhesive to a layer of asphalt saturated asbestos. 

(7) Unsaturated asbestos fastened with an asphaltic adhesive to a 
layer of asphalt-saturated and coated felt. 

Since a woven fabric (burlap or cotton ducking) absorbs a smaller percentage 
of bituminous saturation than a felted fabric, the former when saturated is far less 
weather-resisting. It is preferable, therefore, to use the woven sheet for backing a 
laminated roofing, and thus protect it from the direct action of the weather as much 
as possible, and where it will at the same time fulfil its function of adding to the 
strength of the finished product. 

Processes have also been described involving the use of wire mesh fastened with an 
asphaltic adhesive to an asphalt-saturated felted or woven fabric composed of ani- 
mal, vegetable or mineral fibres ^ but this is not practicable, as the cost of wire mesh 
is prohibitive, and besides is apt to rust out in a short time. Another structure 
consists of a sheet of thin lead embedded in an asphaltic adhesive between two layers 
of tarred felt.^ 

A more practical device consists in fastening a sheet of thin steel with an 
asphaltic adhesive between two layers of treated asbestos. This is marketed in either 
flat or corrugated sheets of 26 to 20 gauge, weighing 125 to 225 lb. per 100 sq. ft. 
net. The flat sheets measure 30 in. by 6 ft., 8 ft., 9 ft. or 10 ft. respectively, 

lU. S. Pats. 446,775 of Feb. 17, 1891 to J. N. Hopper; 539,767 of May 21, 1895 to F. W. Cool- 
baugh and N. M. Goodlett; 767,723 of Aug. 16, 1904 to F. W. Terpenning. 
2U. S. Pat. 441,036 of Nov. 18, 1890 to Arthur Siebel. 



410 



ASPHALTS AND ALLIED SUBSTANCES 




\lm 










m 



and the corrugated sheets 20 in. by 6 ft., 8 ft., 9 ft. or 
10 ft.^ The asbestos surfacing is colored white, terra 
cotta, or dark gray, and waterproofed by impregnation 
with a vegetable drying oil to prevent its being affected 
injuriously by the weather. The material may either be 
used as a siding or roofing, and is strong, Light, rust- 
proof and fire-resisting. 

Flexible laminated prepared roofings may be manu- 
factured either by the continuous or the intermittent 
process. If the former is used, the individual layers are 
first impregnated in a tar or asphalt saturator (p. 395), 
then wound in rolls of large diameter known as " jumbo " 
rolls, and finally joined in the desired number of layers 
and sequence on a form of machine illustrated in Fig. 
133, designed to assemble not exceeding five layers. If 
made on a continuous-process machine, as many saturators 
must be provided as there are layers to be impregnated. 

With the exception of 2- and 3-ply tarred roofings, 
multiple-layered roofings are not manufactured in standard 
weights. The 2-ply tarred roofing ranges between 40 and 
45 lb., and the 3-ply between 60 and 68 lb. in one-square 
rolls. 

Roll Roofings Finished with an Ornamental 
Surface. Numerous devices have been used to 
break the continuity of sheet roofing, by finishing 
it to simulate the appearance of tiles or shingles 
as illustrated in Fig. 134 (A, B, C, D and E). 
One method consists in embossing the sheet in 
imitation of tiles and filling in the depressions 
on the under side with a composition of matter ,2 
another in decorating the surface by hexagonal, 
square or oblong impressions in imitation of 
shingles; ^ coating portions of the surface with 
sand, gravel or other mineral matter and leaving 
adjacent portions uncoated in the form of 
shingles; ^ printing the surface in hexagons, 

1 U. S. Pats. 788,358 of Apr. 25, 1905; reissue 12,475 of Apr. 
24, 1906, and 516,661 of Apr. 3, 1906, all to F. D. Jacobs; also 
845,890 of Feb. 26, 1907 to E. H. Binns; 1,002,301 of Sep. 5. 1911 
to E. T. Newsome; 1,115,714 of Nov. 3, 1914 to T. D. Miller; 
1,167,949 of Jan. 11, 1916 to P. M. Stewart. 

2U. S. Pat. 838,232 of Dec. 11, 1906 to J. O. Ballentine. 

3U. S. Pats. 1,208.595 of Dec. 12, 1916 to W. F. McKay; 
1,214,659 of Feb. 6, 1917 and 1,228,191 of May 29, 1917 both to 
W. P. Dun Lany. 

4U. S.Pat. 1,181,827 of May 2, 1916 to C. S, Bird; 1,250,577 
of Dec. 18, 1917 to S. H. Goldberg. 



BITUMINIZED FABRICS 



411 



squares or oblongs with a black paint; ^ appljring a coating of asphalt 
in designs over a grit surfacing; ^ distributing crushed slate of two or 
more colors in adjoining squares, diamonds, hexagons, or other designs, 
to produce multi-colored effects;^ mixing mineral particles of different 
colors to impart a mottled appearance, etc.^ 

A different procedure consists in creasing 24-in. roofing sheets longi- 
tudinally 3 in. from the edges so that they may be laid over wooden 




(A) 



(B) 



(C) 





(D) (E) 

Fig. 134. — E,oll Roofings Finished in an Ornamental Surface. 



battens If in. square, spaced 20 in. from centres, and in this manner 
break up the surface by a number of standing seams intended to cast 
shadows.^ 

These decorative roofing sheets have become very popular in recent 
years. They are less expensive than composition shingles in view of the 
smaller amount of material required to cover 100 sq.ft. of roof surface, 

1 U. S. Pat. 1,222,594 of Apr. 17, 1917 to M. B. Becker. 

2U. S. Pats. 1,024,549 and 1,024,550 of Apr. 30, 1912 to M. B. Becker. 

3U. S. Pats. 1,082,364 of Dec. 23, 1913 to A. S. Spiegel; 1,157,438 of Oct. 19, 1915 to A. S. 
Spiegel and L. F. Lindley; 1,194,890 of Aug. 15, 1916 to A. S. Spiegel; 1,254,481 of Jan. 22, 
1918 to C. M. Clarke. 

4U. S. Pat. 1,134,086 of Mar. 30, 1915 to F. C. Lowrey. 

5U. S. Pat. 1,210,855 of Jan. 2, 1917 to R. L. Shainwald, Jr. 



412 ASPHALTS AND ALLIED SUBSTANCES 

and are accordingly used where the price of individual shingles cannot 
be afforded. 

Prepared Roofing Shingles. These represent a further development 
in prepared roofings, to produce decorative effects in imitation of wooden 
or slate shingles. This is brought about by cutting the roofing in dia- 
mond or rectangular units adapted to be laid in over-lapping courses. 

One method consists in manufacturing sheets of roll roofing with a 
scalloped or '' serrated " edge intended to be laid in courses so that the 
scalloped portions remain exposed to the weather. ^ This type of pre- 
pared roofing shingle has not proven very successful, as the long strips 
do not adequately provide for the expansion and contraction of the roof 
boards, and unless conditions are exactly right, the roofing is apt to 
wrinkle. 

The foregoing objection is overcome by cutting the prepared roofing 
sheets in the form of individual shingles, usually in rectangular units. 
These may either be of uniform thickness, ^ or they may be tapered so 
the shingles will be thicker at the butts. ^ One form is provided with a 
flap at the butt, adapted to be turned back and nailed underneath;^ another 
is formed with a portion of the shingle cut away on one side, resulting 
in what is known as a '' self -spacing " shingle.^ As manufactured to-day, 
the standard size of individual shingles is 8 by 12f in., intended to be laid 
4 in. to the weather and J in. apart, requiring 424 shingles, or 300 
sq.ft. of shingle surface weighing 220 lb., which is sufficient to cover 100 
sq.ft. of roof surface in three thicknesses. Individual shingles are usually 
made with a slate surface from a No. 48 to 55 raw felt, and carry 
23 to 38 lb. of slate surfacing per 100 sq.ft. of shingle surface, or 70 to 
115 lb. pe" square of shingles. They are sometimes made from a No. 
75 to 80 felt, and finished with a smooth surface. 

A heavier and stiffer type of red or green slate-surfaced shingle is also manu- 
factured weighing 240-250 lb. per square, comprising 424 shingles each measuring 
8 by 12| in. In another modification, the shingles are multi-colored, the upper 
half being surfaced with red slate particles and the lower with green slate so that 
each shingle may be used to present either a red or a green surface depending upon 

lU. S. Pats. 702,614 of June 17, 1902 to W. H. Bache; 742,614 of Oct. 27, 1903 to J. L. M. 
DuFour; 875,099 and 875,595 of Dec. 31, 1907, 876,009 of Jan. 7, 1908, 881,023 and 881,024 of Mar. 
3, 1908, 891,500 of June 23, 1908, and 942,660 of Dec. 7, 1909, all to F. C. Overbury; 966,178 of 
Aug. 2, 1910 to J. L. M. DuFour; 978,333 and 978,334 of Dec. 13, 1910, 1,102,680 of July 7, 1914, 
and 1,130,368 of Mar. 2, 1915, all to F. C. Overbury; 1,126,932 or Feb. 2, 1915 to Herbert Abraham. 

2U. S. Pats. 310,192 of Jan. 6, 1885 to J. T. Edson; 455,271 and 455,272 of June 30, 1891 to 
Hermann Bormann; 845,890 of Feb. 26, 1907 to E. H. Binns. 

3U. S. Pats. 394,033 of Dec. 4, i888 to S. E. Trott; 877,019 of Jan. 21, 1908 to J. W. Troeger; 
886,912 of May 6, 1908 to C. W. Young; 1,197,607 of Sept. 5, 1906 to F. M. EauBchhaupt; 1,191,932 
Re. 14,387 of Oct. 30, 1917, to J. C. Loyer. 

«U. S. Pat. 1,104,998 of July 28, 1914 to F. C. Overbury. 

6 U. S. Fat. 1,244,054 of Oct. 30, 1917, to A. S Spiegel. 



BITUMINIZED FABRICS 



413 



which half is exposed, or if desired variegated colored effects may be used by reversing 
the shingles at intervals. An attachment for cutting roll oofing irto individual 




Courtesy of Guyton & Cumfer Mfg. Ca 
Fig. 135.— Shingle Cutter— Front View. 




Courtesy of Guyton & Cumfer Mfg. Co. 
Fig. 136.— Shingle Cutter— Rear View. 



shingles is illustrated in Figs. 135 and 136. The sheet is first shced into S-in. 
longitudinal strips upon being fed through a gang of circular knives mounted on a 



414 



ASPHALTS AND ALLIED SUBSTANCES 



common shaft, and these in turn are severed into 12 1 in. units by a rapidly revolv- 
ing transverse blade extending the full width of the machine. 

Still another type is stamped from strips composed of a metal core to which 

sheets of waterproofed asbestos are fastened 
on either side by means of asphalt, as 
described on p. 409.^ 

In another ramification the shingles 
are made in larger units (9 by 16 in.), 
to be exposed 5 in. to the weather on lay- 
ing and spaced 6 in. apart as illustrated in 
Fig. 137.2 This is known as the " wide- 
spaced method " and has the advantage of 
requiring less shingle area to cover 100 
sq.ft. of roof surface. Thus, with the cus- 
tomary slate-surfaced fabric weighing 75 lb. 
per 100 sq.ft., it will take 192 9 by 16- 
in. wide-spaced shingles, or a total of 192 
sq. ft. of shingle area, weighing 145 lb. 
to cover 100 sq.ft. of roof surface, 
multiple-shingle strip," consists of two or four units joined 
as illustrated in Fig. 138. The form having 





TT 


"% 












: 

i 
o i_ 


<■■ -9" > 

o ■'//// o 






o 




1 


■o 


^, 


<-e"-> 




'0. 









Fig. 137. 



Courtesy of Flintkote Co. 
-Wide-spaced Shingles. 



The so-called 
together in the form of a flat strip ^ 
square butts 7| in. wide is made 32| in. long (over all) and 10 in. wide, with cut- 
outs 4 by ^ in., and adapted to be exposed 4 in. to the weather. A square will 
include 112 shingle strips of 244 sq.ft. area, weighing 185 lb. A shingle strip is 




'^'^ = 












ir r^'i-^ ' i^ •- ■f 






Courtesy of Flintkote Co. 



Fig. 138.— Multiple Shingle Strip. 



manufactured with diamond-shaped cut-outs extending back 4 in. from either edge (Fig. 
139), and in units measuring 12f by 32f in. over-all. A square includes 112 shingle 
strips measuring 220 sq.ft. in area, and weighing 165 lb. A " reversible shingle 
strip " (Fig. 140A and B) is manufactured with the square butts on one side and dia- 
mond on the other, measuring 32| in. long and 12| in. wide over all. A square 
includes 112 shingles, measuring 260 sq.ft. in area, weighing 195 lb., and may be 
laid with either the square butts or the diamond points exposed, as desired. The 
advantages of the shingle strips are that they may be laid more rapidly than individi- 

»U. S. Pat. 1,059,682 of Apr. 22, 1913 to T. D. Miller. 

2U. S. Pat. 1,145,440 of July. 6, 1915 to Calvin Russell. 

3U. S. Pats. 891,501 of June 23, 1908, 908,125 of Dec. 29, 1908, 1,150.298 of Aug. 17, 1915, all 
to F. C. Overbury; 1,207,523 of Dec. 5, 1916, 1,209,955 of Dec. 26, 1916 both to S. M. Ford; 
1,219,652 of Mar. 20, 1917 to W. F. McKay; 1,243,064 of Oct. 16, 1917 to O. A. Heppes. 



BITUMINIZED FABRICS 



415 



ual shingles, due to the fact that two or more units are coupled together, also that 
it will take a smaller quantity of roofing to cover a 100 sq.ft. of roof area. The 
appearance of the roof when laid is substantially the same as in the case of Individ- 







Courtesy of Flintkote Co. 



Fig. 139. — Diamond Shingle Strip. 




(B) Courtesy of Flintkote Co. 

Fig. 140. — Reversible Shingle Strip. 

ual shingles, but it is not protected with as many layers of fabric, for obvious 
reasons. 

Fastening Devices. Sheets of prepared roofing were originally 
fastened to the roof boards by means of | to 1-in. steel nails, driven 



416 ASPHALTS AND ALLIED SUBSTANCES 

through convex discs composed of American terne plate (thickness IX), 
f to 1 in. in diameter, the nails being spaced 2 in. from centres. Discs 
formed of prepared roofing,^ square caps of enameled metal having a 
raised centre portion,^ steel discs fastened directly to the tops of wire 
nails (known as the " simplex roofing nail ") were next proposed. 

At the present time the " caps " have been almost entirely replaced 
by large-headed roofing nails, of which two types are in vogue, viz.: 





Diameter of Head. 


Diameter of Shank. 


Length of Shank 


American felt roofing nails 


Ts in. 


^in. 


1 in. 


Barbed No. 10 roofing nails... 


re in. 


1 in. 


I in. 



For the better grades of roofing, the nails should either be sherard- 
ized or galvanized, and protected with not less than 37| mg. zinc per 
square centimeter, corresponding to IJ oz. per square foot of surface. ^ 
Sherardizing is preferable to galvanizing, as it affords better protection to 
the steel, assuming that equal weights of zinc are applied in both cases, 
and forms a coating that will not chip or flake off should the nail shank 
or head bend. This is very likely to occur at the junction of the shank 
and head when the nail is driven in place. A well-sherardized nail will 
withstand the weather under normal conditions from ten to fifteen years, 
without further protection, and in the author's opinion constitutes the 
most satisfactory means of rust-proofing. 

With cheaper prepared roofings, it is customary to furnish the nails 
in the '' bright " form, i.e., without being treated, but it then becomes 
necessary to protect the heads when hammered into place, with a 
liberal coating of "lap cement" (p. 470). Although the latter will 
tend to retard corrosion of the steel, the practice is not to be recom- 
mended, where the durability of the roof is an important consideration. 

Other metal fasteners include flat or formed tapes intended to be nailed at inter- 
vals; ^ long strips with spaced perforated concave portions; ^ short strips reinforced 
by having the centre portion raised, and capable of accommodating four nails, illus- 
trated in Fig. 141, known as " roofing cleats ".^ 

lU. S. Pat. 742,589 of Oct. 27, 1903 to B. G. Casier. 
2U. S. Pat. 816,522 of Mar. 27, 1906 to G. B. Wyman. 

3 If a represents the diameter of the nail head, b the average length of the shank, and c the 
diameter of the shank, then the total area of the nail's surface will be equal to: 

11 22 

'— a^H be. 

7 7 

< U. S. Pat. 348,844 of Sept. 7, 1886 to David Harger. 

»U. S. Pats. 887,532 of May 12, 1908 to H. B. Sherman; 967,208 of Aug. 16, 1910 to J. F. 
Leslie. 

«U. S. Pats. 973,902 of Oct. 25, 1910 to W. H. Woerheide; 981,362 of Jan. 10, 1911 to J. H. 
Bell; 985,501 of Feb. 28, 1911 to J. H. Bell; 1,017,611 of Feb. 13, 1912 to H. R. Wardell (Federal 
Reporter of Jan. 12, 1915, 215, 604); and 1,187,532 of June 20, 1916 to H. C. Ketteleon. 



BITUMINIZED FABRICS 



417 



Less expensive fastening devices consist of sherardized or galvanized wires 
which may be looped at intervals, ^ or composed of a series of spaced, perforated 
flattened areas 2 as illustrated in Fig. 142. Another fastener consists of an N- 
shaped piece of wire having one limb pointed for driving into the boards, the other 
ending in a small loop intended to be bent over the 3dge of the sheet at the seam. 
A similar device has been proposed for fastening shingles,^ consisting of a metal 
strip nailed underneath the shingle with one end projecting beyond the shingle and 
intended to be bent over the butt. Another shingle fastener is composed of grooved 
strips of metal to be inserted in between adjacent shingles.* 

Many methods have been devised for protecting the seams and covering 
the nail heads, as for example folding back the upper sheet of roofing after forming 
the seams; ^ driving the nails through the under sheet of roofing only, and then 
cementing the upper sheet over the nails heads; ^ forming the roofing sheets with 





Fig. 141.— Types of Roofing " Cleats. 



Fig. 



Courtesy of The Standard Paint Co. 
142. — Wire Roofing Fastener. 



bevelled edges; ^ providing the edges of the sheets with one or more flaps composed 
of burlap, metal, or the same material as the roofing itself, intended to be folded 
over the nails heads and fastened with hquid lap-cement. The last is known 
as " concealed nailing." ^ 

Methods of Forming Roll Roofing Packages. Roll roofings are pre- 
pared for shipment by winding them on the outside with a heavy 
paper '' wrapper," and packing the '' fixtures " consisting of the nails 
and can of " lap cement " in the core of the roll. Various devices have 
been used for holding the fixtures in place, including sheets of cloth or 
heavy paper pasted over the ends; cylindrical plugs of wood driven in 



1 U. S. PatB. 757,193 of Apr. 12. 1904 and 778,863 of Jan. 3, 1905 to F. S. Howard; 1,242,675 of 
Oct. 9, 1917 to S. M. Ford. 

»U. S. PatB. 1.237,270 of Aug. 21, 1917 to Herbert Abraham; and 1,225,972 of May 15, 1917, 
to H. C. Ketteleon. 

« U. S. Pat. 978,334 of Dec. 13. 1911 to F. C. Overbury. 

«U. S. Pat. 1,153,152 of Sept. 7. 1915 to Francis Brucker. 

»U. S. Pat. 60,708 of Jan. 1, 1867 to C. J. Fay. 

• U. S. Pat. 713,588 of Nov. 18, 1902 to John Ayrault. 

TU. S. Pat. 813.163 of Feb. 20, 1906 to W. J. Moeller. 

sU. S. Pat. 632.825 of Sept. 12. 1899 to R. J. Redick; 636,022 of Oct. 31, 1899 to G. D. Crabbs 
and W. H. Pendery, 652,150 of June 19, 1900 to F. W. Terpenning; 669,315 of Mar. 5. 1901 to 
D. P. Whitmore; 835,889 of Nov. 13, 1906 to W. J. Moeller; 8.55,757 of June 4, 1907 to G. D. 
Crabbs and W. H. Pendery; 868.930 of Oct. 22, 1907 to A. E. Kirk; 984.860 of Feb. 21, 1911 to 
F. E. Smith. 



418 . ASPHALTS AND ALLIED SUBSTANCES 

the openings at the end of the roll and fastened together with wire; ^ 
using a paper wrapper wider than the roll, turning over the edges into 
the core and wedging into place with cylindrical plugs; ^ sealing the 
openings of the core with plaster of paris plugs; ^ constructing the 
openings of the core by driving wooden wedges between the convolu- 
tions at the ends of the roll; ^ covering the ends of the roll with 
wooden discs wired together; ^ covering the ends with metal discs 
wired together; ^ covering the ends with metal discs fastened together 
with a light metal rod; '^ metal discs held in place by projecting flanges; ^ 
packing the fixtures in an elongated cylindrical cardboard case, which 
at the same time serves as a mandrel for the roll; ^ wrapping the nails 
and can of lap-cement in a paper or cloth package provided with a flap 
which is inserted between the inner convolutions of the roll of roofing 
as the sheet i wound on the machine ^^ etc. Most of the rolls shipped 
at the present time are protected with " heads," of cloth pasted in 
place. 

Method of Laying Prepared Roofings and Shingles. Prepared roof- 
ings may either be laid in a single course, or in a so-called " built-up " 
form, composed of two or more bituminated sheets constructed on the 
roof of the building. The single course method is adapted only for 
application over wood, whereas built-up roofs are equally suitable for 
use over wooden or concrete roof decks. 

Laying the Fabrics in a Single Course. In this case the sheets are 
laid with 2-in. seams and cross-seams, the joints being sealed with 
liquid lap-cement, and fastened with large headed nails, or with any 
of the o her devices described. The usual method of forming the seams 
is illustrated in Fig. 143 {A and B). The same method is followed in 
laying single- or mult pie-layered bituminated roofing sheets in one 
course. Where the sheet is sui faced with moderately fine mineral mat- 
ter on but one side, it is advisable to lay this against the roof boards.^ ^ 
A single course of multiple-layered roofing, composed of burlap cemented 
between two layers of asphalt-saturated and coated felt is introduced 

lU. S. Pat. 694,304 Feb. 25, 1902 to C. S. Bird and J. B. Hanscom. 

a U. S. Pat. 803,713 of Nov. 7, 1905 to H. M. Reynolds. 

3 U. S. Pat. 852,397 of Apr. 30, 1907 to W. P. Penney. 

«U. S. Pat. 713,938 of Nov. 28, 1902 to W. H. Bache. 

6U. S. Pat. 873,046 of Dec. 10, 1907 to F. S. Howard. 

6U. S. Pat. 742,558 of Oct. 27, 1903 to W. H. Bache; 874,160 of Dec. 17, 1907 to Purlan 
Buckborough. 

7U. S. Pats. 825,239 of July 3, 1906 to M. C. Ohnemus; 919,607, 919,608 and 919,739 of 
Apr. 27, 1909, and 923,362 of June 1, 1909, all to G. W. Loughman. 

8U. S. Pats. 996,510 and 996,511 of June 27, 1911, both to G. J. Oetsch. 

9U. S. Pat. 980,406 of Jan. 3, 1911 to B. G. Casler. 

"Canadian Pat. 143,374 of Oct. 15, 1912 to C. W. Dohm. 
• " U. S. Pat. 840,103 of Jan. 1, 1907 to R. W, Bird. 



BITUMINIZED FABRICS 



419 



between two layers of sheathing boards for covering freight cars, the 
function of the upper layer being to protect the roofing from injury.^ 
Roofs Constructed of Two or More Courses of Fabrics.^ If used 
over wood, it is customary to first install a layer of sheating paper 
(not necessarily bituminized), to prevent the melted compound from 
dripping into the building, also to purposely separate the built-up roof 
from the wooden boards, thus allowing the latter to shrink without 
danger of tearing the roofing. This layer of sheathing paper should 
not be included in counting the total number of courses or '* plies " 
in the built-up roof. 

Prevailing Winds 

z. 



yy^/7- .^ 

Cemenh 
Boarc/d,^ 




Courtesy of The Standard Paint Co. 
Fig. 143. — Laying Roll Roofing in Single Course. 

A 2-ply built-up roof laid over wood and concrete respectively, 
composed of two courses of prepared roofing, is shown in Fig. 144 
(A and B). A 3-ply built-up roof laid over wood and concrete com- 
posed of 1 course of asphalt-saturated felt with 2 courses of single 
layered prepared roofing, is shown in Fig. 145 (A and B). The built- 



1 U. S. Pat. 845,414 of Feb. 26, 1907 to Samuel Herbert. 

2 U. S. Pats. 40,542 of Nov. 3, 1863 to L. S. Mills and C. H. Smith; 61,878 of Feb. 5, 1867 to 
John Scanlon; 147,962 reissue 8414 of Sept. 10, 1878; 179,131 of June 27, 1876 to Lewis Peirce; 
270,943 of Jan. 23, 1883 to S. L. Foster; 296,163 of Apr. 1, 1884 to Levi Haas and Dennis Howarth; 
331,971 of Mar. 17, 1885 to T. H. White; 677,058 of June 25, 1901 to Emil Borgeson and Axel Wen- 
ncrberg; 712,193 of Oct. 28, 1902, to F. L. Kane; 798,131 of Aug. 29, 1905 to F. W. Gezelschap 
and Arthur Winding; 842,079 of Jan. 22, 1907 to E. R. Campbell; 846,572 of Mw- 12, 1907 to C. 
J. Kunzler; 1,230,396 of June 19, 1907 to F, L. Foster, 



420 



ASPHALTS AND ALLIED SUBSTANCES 



up roofs may be finished " smooth " as shown in the figures, or they 
may be flooded with melted bituminous compound and slag or gravel 
embedded therein while the compound is hot. 




Courtesy of The Standard Fair.t Co. 

Fig. 144. — Two-ply Built-up Roofs over Wood and Concrete. 

A well-known type of 5-ply roof constructed of tarred felt cem.ented 
together with coal-tar pitch and surfaced with either slag or gravel, laid 
over wood and concrete respectively, is shown in Fig. 146 (A and B), 



BITUMINIZED FABRICS 



421 



Lmjing SJiingle Roofs. It is customary to lay 8 by 12J in. prepared 
roofing shingles by exposing them 4 in. to the weather, as illustrated in 
Fig. 147, which will be found self-explanatory. 



.■Groove for Flashing 




Groove for Flashmq 




J Concrete \ " 



Courtesy of The Standard Paint Co. 
Fig. 145.— Three-ply Built-up Roofs over Wood and Concrete. 



Rating of Prepared Roofings and Shingles by the Underwriters' Laboratories, 

Inc., The Underwriters' Laboratories, Inc., of Chicago, estabHshed and maintained 



422 



ASPHALTS AND ALLIED SUBSTANCES 



by the National Board of Fire Underwriters, classify fire retardant roofings into 
three groups,^ viz.: 

Class A. Includes roof coverings which are effective against severe fire exposures. 
Under such exposures, roof coverings of this class are not readily flammable, and do 
not carry or communicate fire; afford a fairly high degree of heat insulation to 
the roof deck; do not slip from position; possess no flying brand hazard; and do 
not require frequent repairs in order to maintain their fire-resisting properties. 

This class includes the following types: 









(A) (B) 

Courtesy of Barrett Company. 

Fig. 146. — Five-ply Built-up Roofs over Wood and Concrete. 

(1) Five-ply built-up roofs composed of coal-tar- or asphalt-saturated rag felt 
surfaced with bricks, tiles, cement, gravel or slag, containing 80 to 85 lb. of tar 
or asphalt saturated rag felt, 150-200 lb. of coal-tar pitch or asphalt, not less than 
400 lb. of gravel or 300 lb. of slag per 100 sq.ft., and hmited to combustible or 
non-combustible roof decks, having inclines not exceeding 3 in. to the foot, hori- 
zontal. 



J Bulletin dated June 29, 1916; also list of Inspected Mechanical Appliances issued by the 
Underwriters' Laboratories, Inc., July, 1917. 



BITUMINIZED FABRICS 



423 



(2) Three-ply built-up roofs containing not less than 40 lb. of asphalt-saturated 
asbestos felt, and 37 lb. of asphaltic cement per 100 sq.ft., and limited to non-com- 
bustible roof decks with inclines not exceeding 6 in. to the foot horizontal. Also 
4- and 5-ply built-up roof coverings containing not less than 60 lb. of asphalt-satu- 
rated asbestos felt and 45 lb. asphaltic cement per 100 sq.ft., and limited to com- 
bustible or non-combustible roof decks with inclines not exceeding 6 in. to the foot 
horizontal. 

(3) A single course of laminated roofing composed of 4 sheets of asphalt-satu- 
rated asbestos felt, cemented together with an asphaltic adhesive, weighing not less 
than 60 lb. per 100 sq.ft., and limited to combustible or non-combustible roof decks, 
with inclines exceeding 3 in. to the foot horizontal. 




Courtesy of The Standard Paint Co. 

Fig. 147. — Laying Individual Shingles. 



Class B. Includes roof covering which are effective against moderate fire expo- 
sures. Under such exposures, roof coverings of this class are not readily flammable, 
and do not readily carry or communicate fire; afford a moderate degree of heat 
insulation to the roof deck; do not slip from position; possess no flying brand 
hazard; but may require occasional repairs in order to maintain their fire-resisting 
properties. 

Bii^uminous roof coverings falling in this class include: 

(1) Three-ply built-up roofs containing not less than 48 lb. of coal-tar- or asphalt- 
saturated rag felt, 90 lb. of coal-tar pitch or asphaltic adhesive, 400 lb. of gravel 
or 300 lb. of slag per 100 sq.ft., and limited to combustible or non-combustible roof 
decks, having incHnes not exceeding 3 in. to the foot horizontal. 

(2) Three-ply built-up roofs containing not less than 46 lb. of asphalt-saturated 
asbestos felt, and 40 lb. of asphaltic adhesive, limited to combustible and non- 



424 ASPHALTS AND ALLIED SUBSTANCES 

combustible roof decks, capable of receiving and retaining nails, and to inclines not 
exceeding 6 in. to the foot horizontal. 

(3) Three-, 4- or 5-ply built-up roofs containing both asphalt-saturated asbestos 
and rag felts cemented together with an asphaltic adhesive. Various specifications 
are approved for this class of coverings. The 5-ply may be used on combustible 
roof decks, and is limited to inclines not exceeding 3 in. to the foot horizontal; the 
4-ply may be used on combustible roof decks but is limited to inclines not exceed- 
ing 3 in. to the foot horizontal; and the 3-ply is limited to non-combustible roof 
decks, and to inclines not exceeding 3 in. to the foot horizontal. 

(4) A single course of laminated roofing composed of either tvvo or three sheets 
of asphalt-saturated asbestos felt cemented together with asphaltic adhesive, weigh- 
ing not less than 45 lb. per 100 sq.ft., and Umited to combustible and non-combus- 
tible roof decks capable of receiving and retaining nails, and to inclines exceeding 
3 in. to the foot horizontal. 

Class C. Includes roof coverings which are effective against light fire exposure. 
Under such exposures, roof coverings of this class are not readily flammable, but 
may carry and communicate fire; afford at least a slight degree of heat insulation 
to the roof deck; do not slip from position; may possess a slight flying brand 
hazard; and may require fairlj^ frequent repairs or renewals in order to maintain 
their fire-resisting properties. 

This class includes one course of 2- or 3-ply (heavy and extra heavy) single- 
layered prepared roofing composed of asphalt-saturated and coated rag felt (finished 
with either a smooth, sanded or grit surface); also prepared roofing shingles com- 
posed of asphalt-saturated and coated rag felt (finished with either a smooth, 
sanded or grit surface). These are limited to combustible and non-combustible 
roof decks, capable of receiving and retaining nails, and to inclines exceeding 3 in. 
to the foot horizontal in the case of roll roofings, and exceeding 4 in. to the foot 
horizontal in the case of shingles. 

In brief, the following minimum requirements are proposed by the Under- 
writers' Laboratories, Inc. for the Class C roofings: 

Dry felt to be uniform in thickness, texture and quality, averaging not less than 
10.4 lb. per 100 sq.ft. (corresponding to No. 50 on felt maker's scale), with a mini- 
mum weight of 10 lb. (corresponding to No. 48). 

Saturating and coating compounds to be of an asphaltic nature, having a flash- 
point of not less than 210° C. (410° F.) bj^ the Pensky-Martens closed-cup method 
and an ignition-point of not less than 400° C. (752° F.) as determined by the Under- 
writers' Laboratories' standard method. 

Surfacing materials to be non-combustible, including talc, soapstone, mica, slate, 
rock, sand, pebbles, gravel, terra cotta, crushed vitreous materials, etc. The dust- 
ing powder should not exceed 3 lb. per 100 sq.ft. The coarse surfacing materials 
to be free from dust, or foreign matter which would interfere with their adhesion, 
and to be well embedded in the coating compound. 

Nails to be galvanized, and not less than f in. long for roll roofings, and 1 in. 
long for shingles. Bright nails when exposed to the weather should be protected 
with a rust-proof coating. 

Smooth-surjaced roll roofings to average not less than 37 lb. per 100 sq.ft. (ex- 
clusive of nails and cement) with a minimum of 34.5 lb. 

Grit-surfaced roll roofings to average not less than 37 lb. per 100 sq.ft. (exclusive 
of surfacing material, nails and cement), with a minimum of 34.5 lb. 



BITUMINIZED FABRICS 



425 



Indiiidual and strip shingles to be in such form, shape and size that there will 
be at least one thickness of roofing material at the thinnest point when laid, and 
that no portion of the deck boards will be exposed upon cutting away the weather 
portion of the shingles or strips along a line through the nails in the strips which 
secure them to the roof deck. The average weight of a single thickness of the 
shingles exclusive of surfacing material, wrappers, and fixtures shall not be less than 
37 lb. per 100 sq.ft. with a minimum of 34.5 lb. 

Multiple-layered prepared roofings and shingles to be composed of two or more 
thicknesses of asphalt-saturated rag felt, cemented together and coated with an 
asphaltic material, with or without mineral surfacing. These are to comply in all 
essential particulars with the requirements for prepared roofings and shingles com- 
posed of a single thickness of felt. 

The foregoing classifications exclude wooden shingles, which constitute the 
greatest competitor of prepared roofings. Figures compiled by the U. S. Dept. of 
Agriculture ^ indicate that from 1904 to 1912 the output of wooden shingles in the 



i^iO 
























Cy 












.^,. 

















'v 






n£i> 


<t'^^,. 












ci 




V 






^nO>-'^ 


-<i:^.' 














v 




















f:^'^ 




s 




^ " 










"^-v^ 1 J 




















-' 


■ ::____^ 


&^ 




c?« 








ROOFING^ 


^ 




taiH. 






... 




^ 






BSTITUZ5J 


ANDJ^ 
















TOTMja 




















-r^Tn'REA'-'Li::^^^^-— 
















^ 1 


^I^ 


























































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SLA T£ 


ROOFING 
















36 0^ 








■ 















/SO-^ 190$ 1908 1010 1312 fdl4 I$I5 

Fig. 148. — Chart of Annual Production of Roofings in the U. S. 

United States fell from 17| to 14| milHon squares, and from 1909 to 1915 from 18 
to \2\ million squares; further, that the production of substitute roofings (includ- 
ing prepared roofings, prepared roofing shingles, slate, tile, etc.) increased from 4| 
to 13| million squares from 1904 to 1914. This is illustrated graphically in Fig. 
148. The total production of the substitute roofings manufactured in 1914, estimated 
at 13,605,835 squares (excluding tar and gravel roofs), is apportioned as follows: 

Cement, tile and miBcellaneous. 0.4% 

Slate tile 11% 

Asphalt shingles 2 . 4% 

Metal shingles and tiles 6.3% 

Slate (1913) • 8-2% 

Prepared roofings, including asbestos roofings and shingles 81 . 6% 

Total 100.0% 

The author estimates that in 1917 there were produced 20 million squares of 
composition roll roofings and 2 miUion squares of composition shingles. 



^ Kept. No. 117 the " Substitution of other Materials for Wood Study of the Lumber Industry, 
Part XI, by Rolf Thelan, Washington, D. C, 1917. 



426 ASPHALTS AND ALLIED SUBSTANCES 



BITUMINIZED FLOOR COVERINGS 

Methods of Manufacturing. These first appeared on the market 
in 1910 as a substitute for linoleum, and have since enjoyed steadily 
increasing sale, due to their lower price, superior waterproof properties 
and remarkable resistance to wear and tear under foot. They are 
prepared from an asphalt-saturated rag felt printed on the surface in 
colored patterns, manufactured with or without a backing of burlap, 
and in all cases faced on the underside with a suitable paint or wash.^ 
When burlap is used, the asphalt-saturated felt may be regarded as 
replacing the central layer of oxidized linseed oil, resins, wood flour, 
powdered cork, colored pigments and mineral filler ordinarily employed 
in manufacturing printed linoleums. Where no burlap is used, the 
asphalt-saturated rag felt may be viewed as the equivalent of both the 
central layer and burlap backing. 

The bituminized floor covering is less frequently composed of an 
asphalt-saturated rag felt carrying a moderately thick layer of the lino- 
leum composition (oxidized linseed oil, resins, wood flour, powdered 
cork, colored pigments and filler) on the surface, and the usual paint 
or wash on the back.^ 

In manufacturing the floor covering, a sheet of rag felt of high 
tensile strength, great uniformity in texture and thickness, is first satu- 
rated with an asphaltic mixture having a somewhat higher fusing-point 
and greater hardness than used for manufacturing roofing (p. 391). 
The asphalt-saturated felt prepared in this manner is first allowed to 
season, and then sized on the upper surface with an aqueous solution 
of some glutinous substance, such as wheat or rye flour, casein,^ animal 
glue and silicate of soda,"* or the like, with or without the admixture 
of a suitable filler, such as ground shale (known commercially as 
*' talckene ")> clay, siliceous minerals, etc. The function of the sizing 
coat is to prevent the dark-colored hydrocarbons in the felted fabric 
from working their way through and discoloring the paint subsequently 
applied to the surface. 

When the size is dry, the fabric is " primed " or " filled " with a 
mixture composed of 2 to 4 parts of " gloss oil " ^ and 1 part of com- 

1 U. S. Pat. 1,184,584 of May 23, 1916 to W. D. Snow. 

« U. S. Pat. 1,132,647 of Mar. 23, 1915 to E, L. Blabon. 

» U. S. Pat. 1,176,853 of Mar. 28, 1916 to George Prifold; Ger. pat. appl. 72.226 of Feb. 13, 1913 
to the Barrett Manufacturing Co. 

*U. S. Pat. 1,008,296 of Nov. 7, 1911 to Judd Smith. 

6 Consisting of linseed oil which has been heated to a temperature in the neighborhood of 
530° F. with 1 to 2 per cent of red lead, litharge, or other suitable dryers, until the oil assumes 
the coneietency of heavy molasses. 



BITUMINIZED FABRICS 427 

mercial " boiled " linseed oil, ground through a paint mill with a 
mixture of filler and yellow ochre, and thinned to spreading consistency 
with a volatile petroleum distillate. The function of the ochre is to 
impart a so-called '^ linoleum " color to the mixture. The filler and 
pigment should be added in sufficient quantity to cause the paint to 
assume a ''flat" finish on drying, and the petroleum distillate to 
reduce the mixture of oil and pigments to proper spreading consistency. 
The priming coat is applied either to one or both surfaces of the 
sized bituminized fabric by running it through a pair of rollers or in 
some cases a set of rubber or leather squeegees. 

The sheet is then festooned in a steam-heated drying chamber, 
maintained at 110 to 140° F., until the priming coat has dried hard, 
whereupon it is passed through a set of " grinding rolls " composed of a 
suitable abrasive, to smooth and level it off. 

Method of Printing and Graining. If the flooring is to be finished in 
designs to produce what is known to the trade as " print goods," it is 
next passed through a printing machine of the type ordinarily used for 
manufacturing linoleum, which will apply two or more colors in pre- 
determined patterns or designs. These may be varied at will by chang- 
ing the '' print blocks " or dies used on the machine. The colored print- 
ing mixture contains suitable proportions of " gloss oil," mixed with 
colored pigments in quantities sufficient to color the mixture, but not to 
overcome the gloss when dry. The printed goods are again festooned 
in the drying chamber where they are allowed to remain until the surface 
coating dries hard. 

In manufacturing " grained " floor coverings in imitation of wood, the sized 
and primed fabric after being smoothed and levelled, is passed through a " Posse- 
lius " graining machine, which appUes colored paint in the form of a graining to 
imitate the wood selected. This is allowed to dry and the surface finished with a 
coat of high-grade floor varnish, in some cases containing " gloss oil " when it is 
desired to increase the pUabihty of the finishing coat. The fabric is then sus- 
pended in the drying oven and heated until hard and tough. 

The reverse ide of the floo ing is usually surfaced in a dull red tint, similar to 
that used for finishing burlap-backed hnoleum. Two general methods are followed. 
One consists in coating the under side of the asphalt-saturated felt with the red 
paint after it has been sized, but before the priming coat, which is thereupon applied 
to the upper surface only. An alternative method consists in simultaneously 
coating both the upper and lower surfaces of the sized fabric with priming coats, 
drying, and then applying the red paint to the back. In either case the red paint 
consists of a mixture of rosin varnish, gloss oil, boiled linseed oil, ground shale or 
other filler, mixed with sufficient red iron oxide, to impart the desired shale, and 
thinned with petroleum distillate to spreading consistency. 

The raw felt used ranges from No. 36 to No. 60; the asphalt-saturated product 
weighs from 16-32 lb. per 100 sq.ft.; the combined weight of the coats of paint 



42S ASPHALTS AND ALLIED StJBSTANCEg 

on the front and back surfaces 10 to 15 lb, per 100 sq.ft.; the finished weight of 
flooring (when manufactured without an intermediate layer of linoleum composition) 
25 to 45 lb. per 100 sq.ft.; the thickness of the coats of paint 1^2 mils; the 
thickness of the finished product 50-75 mils; and the dimensions of the rolls as 
marketed 74 in. by 30-33 yds. 

Bituminized floor coverings after being sized are sometimes coated with a 
moderately thick layer of linoleum composition, containing oxidized linseed oil, 
resins, ground cork or wood flour, mineral fillers, and colored pigments. This lino- 
leum layer may be applied in patterns of variegated colors running all the way 
through, known to the trade as " inlaid " goods, or it may be applied in a uniform 
color, and the surface printed as in the foregoing. Floorings having the patterns 
printed directly on the sized and primed felt are less expensive, and from all reports 
wear better than the type carrying the intermediate layer of linoleum composition. 

Bituminized floorings are also marketed in the form of rugs, with a border printed 
around the edges, ^ in some cases reinforced with a marginal stitching embedded 
underneath the surface-coating. ^ 

WATERPROOFING MEMBRANES 

The term '' membrane " as applied to waterproofing was originally 
suggested by E. W. DeKnight, and alludes to a continuous sheet of bitu- 
minized fabric surrounding the structure to be waterproofed. The mem- 
brane system is also sometimes termed the '^ elastic " method, to distin- 
guish it from the '' integral " or " rigid " method of waterproofing (p. 457). 
The former is ordinarily used for waterproofing structures in the course 
of erection, and particularly the portion below ground level, including 
foundations of buildings, retaining walls, railway bridges, tunnels, sub- 
ways, reservoirs, masonry tanks, swimming pools, etc. The fabric 
constituting the membrane may be felted or woven, or a combination 
of the two. 

Materials Used. The materials ordinarily used for this purpose 
include the following- 

Fabrics: 

(1) Tarred felt. 

(2) Asphalt-saturated felt. . 

(3) Raw burlap or duck. 

(4) Tarred burlap or duck. 

(5) Asphalt-saturated burlap or duck. 

(6) Asphalt-saturated and coated felt surfaced with fine mineral 

matter, moderately coarse embedded mineral matter, wood- 
flour or sawdust. 

(7) A laminated sheet of bituminated fabric composed of bituminized 

felt, burlap or duck, used alone or in various combinations. 

1 U. S. Pat. 1,249,734 of Dec. 11, 1917 to F. B. Foster. 

2 U. S. Pat. 1,255,095 of Jan. 29, 1918 to R. G. Jackson. 



BITUMINIZED FABRICS 429 

Bituminous Adhesive Compounds: 

(1) Coal-tar pitch or mixtures of coal-tar pitch with water-gas tar 
pitch. 

(2) Asphaltic compounds. 

The weight of felted fabrics used for waterproofing purposes varies 
widely, but the best practice provides that the dry felt shall not be 
less than No. 30 on the felt makers' scale (6.25 lb. per 100 sq.ft.) 
and the bituminized felt not less than 14 lb. per 100 sq.ft. Saturated 
and coated felts are also made in various weights ranging from 14 lb. 
to 70 lb. per 100 sq.ft. 

Of the woven fabrics, burlap is generally employed, varying in weight 
from 10 to 20 oz. per square yard after saturation. The use of a cotton 
fabric is advocated instead of burlap, since cotton is less liable to rot 
on continuous contact with moisture, but on the other hand it is more 
expensive. Either the cotton or burlap may be made more resistant 
to decay by impregnation with a copper sulphate solution and drying 
before it is waterproofed with bituminous materials. Copper sulphate 
acts as a preservative and prevents the fibres hydrolyzing. The finished 
product should carry from 60 to 66f per cent of bituminous matter. 
No definite statements can be made regarding laminated fabrics com- 
posed of felt and burlap, since these vary widely in their structure 
and weights. 

There has been much discussion v/hcther coal tar or asphaltic prod- 
ucts are superior for waterproofing masonry.^ The present practice 
seems to favor the use of asphaltic products when they are to be sub- 
jected to air, sunlight or vibration, and the use of coal-tar products 
where the waterproofing is protected from these agencies. This con- 
forms with the author's experience. 

The following proposed tentative specifications (1917) for coal-tar-saturated felt 
have been proposed by Committee D-8 of the American Society for Testing Mate- 
rials: 

The saturant to be derived from pure coal tar; the finished product to weigh 
not less than 14 lb. per 100 sq.ft.; the material extractable with hot carbon disul- 
phide shall not be more than 60 per cent nor less than 45 per cent; the loss on 
heating to 105° F. for twenty-four hours shall not exceed 6 per cent; the raw felt 
shall not contain less than 75 per cent of cotton and wool fibres; the tensile strength 
of a specimen 1 in. wide shall not be less than 25 lb. when cut in the direction of 
the length of the sheet, nor less than 10 lb. when cut across the sheet; the raw felt 
shall not contain more than 8 per cent of ash. 

In the case of asphalt-saturated felt, the finished product shall not weigh less 
than 14 lb. per 100 sq.ft.; contain not exceeding 65 per cent nor less than 50 per cent 

1 " Coal tar and Asphalt Pyoducts for Waterproofing," by S. T. Wagner, Chem. Eng., 18, 224, 
1914. 



430 ASPHALTS AND ALLIED SUBSTANCES 

extractable with carbon disulphide; lose not exceeding 2.5 per cent on heating to 
105° F. for twenty-four hours, nor shall the product after this test be hard or 
brittle; the fibres present in the raw felt shall consist at least of 75 per cent of 
cotton and wool fibres; the tensile strength of a specimen 1 in. wide shall not be 
less than 25 lb. when cut in the direction of the length of the sheet, nor less than 
10 lb. when cut across the sheet. 

The American Society for Testing Materials (1917) proposes the following tenta- 
tive specifications for creosote oil to be used as a priming coat in conjunction with 
coal-tar pitch: 

The creosote oil shall be a pure tar distillate free from any substance foreign 
thereto; it shall be entirely fluid at 100° F.; its specific gravity at 100° F. shall 
not be less than 1.00 nor more than 1.06; it shall show less than 1 per cent insol- 
uble in hot benzol; when distilled according to the standard method (p. 522) it 
shall yield not exceeding 2 per cent of water, not exceeding 5 per cent distilling 
under 200° F., not exceeding 50 per cent nor less than 30 per cent distilling under 
235° C, and not exceeding 15 per cent of residue at 355° C. which must be soft 
in consistency. The specific gravity at 100° F. of the fraction distiUing between 
235 and 315° C. shall not be less than 1.00. 

Similarly, the proposed tentative specifications for the primer to be used in 
conjunction with asphaltic adhesives, are as follows: 

The primer shall consist of a paint containing an asphaltic base complying in 
every respect with the asphaltic adhesive compound (p. 422), thinned to ordinary 
paint consistency with petroleum distillate having an end point on distillation of 
not above 260° C, of which not more than 20 per cent shall distil under 120° C. 

The specifications for coal-tar pitch and asphaltic adhesives are given in Chapter 
XXVI. 

Preparing of the Underlying Surface. To insure the courses of bitu- 
minized fabric adhering properly to the underljdng surface and to 
each other, the following precautions should be observed: 

(1) Where the membrane is to be applied below grade, an adequate 
drainage system must be provided so that the masonry surface will be 
thoroughly dry during the installation of the waterproofing. 

(2) It is of the utmost importance that the work should not be 
undertaken in rainy, snowy or very cold weather. 

(3) Concrete surfaces should be brushed, scraped or chipped to 
remove all sharp projections which would puncture the waterproofing; 
also any dirt, foreign matter or cement which may have been raised 
to the surface during the placing of the concrete. 

(4) Masonry surfaces should be primed with creosote oil when 
coal-tar products are to be used, or with an asphaltic paint when 
asphaltic products are to be used for waterproofing. 

(5) Metal surfaces should be cleaned to remove all rust, scale, 
dirt or grease, and primed with a paint containing either coal-tar 
pitch or an asphaltic base, depending upon the character of water- 
proofing used. 



BITUMINIZED FABRICS 



431 



(6) The floors of steel railroad bridges should first be covered with 
a 1 : 3 : 5 concrete containing | in. stone or gravel, the surface of which 
when set and dry should be treated as specified in (3). 

(7) When coated fabrics are used, the adhesion may be promoted 
by omitting the coating from one side of the saturated felt,^ since 
the melted bituminous adhesive forms a better bond with plain saturated 
felt than felt surfaced with a bituminous coating of harder consistency. 

(8) By surfacing saturated and coated felts with wood flour, fine 
sand, or sawdust, instead of talc, soapstone or other finely divided 
mineral filler, because the mineral powders exert a repellant action on 
the melted bituminous adhesive. 

(9) When burlap is used in a single sheet, it is customary to 
manufacture it with the bituminous coating applied in such a manner 
that the meshes between the strands will remain open, the theory being 
that the melted adhesive will fill these and thus key itself more securely 
to the bituminized fabric. 

(10) Not less than 25 lb. of coal-tar pitch or asphaltic adhesive shall 
he applied per 100 sq.ft. of underlying fabric or masonry. 

Selecting and Installing the Waterproofing Membrane. Whether a 
felted or a woven fabric or a combination of the two is to be used, de- 
pends upon the character of the w^ork and the preference of the engi- 
neer in charge. A woven fabric is more pliable, stronger, and less liable 
to tear or break when bent over sharp corners, but to counterbalance 
these, the felted fabric is less expensive, more durable and more resist- 
ant to moisture. Modern practice accordingly favors a combination 
of the two. 

The number of courses of bituminized fabric to be applied depends upon the 
head of water encountered, the factor of safety sought and the views of the engineer 
in charge of the work. There is no standard practice followed in this connection. 
Where tarred- or asphalt-saturated felt weighing 14 lb. per 100 sq.ft. is used, the 
following figures will serve as a safe guide: 





Pressure in Pounds per 


Average Pressure in 


Number of Courses 


Hydrostatic Head. 


Square Foot under 


Pounds per Square Foot 


Tarred or Asphalt-satd. 




Floor. 


agairst Side walls. 


Felt to be Used. 





0.0 


0.0 


2 


1 


62.5 


31.2 


3 


2 


125.0 


62.5 


4 


6 


375.0 


187.5 


5 


8 


500.0 


250.0 


6 


10 


625.0 


312.5 


7 


15 


937.5 


468.7 


8 


20 


1250.0 


625.0 


9 



lU. S. Pat. 819,450 of I\"ay 1. 1^C0 to F. C. Overbi:ry. 



432 ASPHALTS AND ALLIED SUBSTANCES 

The fabrics should always be laid " shingle fashion," and all the layers applied 
in the same direction. 

(a) When the membrane is to be composed of two courses, lay the fabric 
shingle fashion, lapping each course 1 in. more than half the width of the preceding 
one. 

(6) When the membrane is to be composed of three courses, lay the fabric 
shingle fashion, lapping each course 1 in. more than one-third the width of the 
preceding one. 

(c) When the membrane is to be composed of four courses, first cover the sur- 
face with two layers of fabric laid shingle fashion, lapping each course 1 in. more 
than half the width of the preceding one, and then follow with two additional 
courses installed in the same manner. 

(d) When the membrane is to be composed of five courses, follow the procedures 
indicated in (b) and (a) respectively. 

(e) When the finished membrane is to be composed of six courses, duplicate the 
procedure outlined in (b). 

In the case of railroad bridges where the conditions are extremely severe, the 
following alternative specifications are recommended: ^ 

(1) From four to six courses of bituminized felt. 

(2) A middle course of bituminized duck with two courses of bituminized felt 
on either side. 

(3) A bottom course of bituminized felt, followed by two courses of bituminized 
duck with two upper courses of bituminized felt. 

(4) Two or three courses of bituminized duck. 

(5) Combinations of the foregoing with asphalt mastic (see Table XXXIII, p. 434). 

The waterproofing specifications for subway construction issued by the Engi- 
neering Department of the Public Service Commission of the State of New York 
(Section 189), read as follows: 

" The fabric must be rolled out into the pitch or asphaltum while the 
latter is hot, and pressed against it so as to insure its being completely stuck 
over its entire surface, great care being taken that all joints are well broken by 
overlapping, and that unless otherwise permitted, the ends of the rolls of the 
bottom layers are carried up on the inside of the layers on the side, and 
those of the roof down on the outside of the layers on the side, so as to secure 
a full lap of at least 1 tt. Especial care must be taken with this detail." 

It is extremely important that the work should be continuous. A lack of con- 
tinuity will be fatal to any membrane, since the water is sure to find its way 
through. Each layer of pitch, asphalt or other adhesive should com-pletely cover the 
surface over which it is spread, without breaks, blow-holes or other imperfections. 
The fabric must be rolled out smoothly, and pressed into the hot cementing mate- 
rial, to insure its sticking thoroughly and evenly. Where it becomes necessary to 
temporarily discontinue the work, laps at least 12 in. wide must be provided to 
join with the ensuing section of the waterproofing. On walls connecting with 
floors, the ends of the floor layer should be carried through the wall and turned 
upwards outside, whereupon the fabric on the outside of the walls should be carried 
down over the ends of the floor layer, lapping at least 12, and preferably 24 i:i. 

1 " The Waterproofing of Solid Steel-floor Eailroad Bridges," by S. T. Wagner, Proc. Am, Soc. 
Civil Eng., 79, 30G, 191.5, 



BITUMINIZED FABRICS 433 

On connecting the wall with the roof work, the layers of fabric from the roof should 
be carried down over the outside of the wall layers forming a lap at least 12, and 
preferably 24 in. 

Protecting the Waterproofing Membrane. After installing the mem- 
brane, it must be protected against any mechanical injury which is 
liable to occur on backfilling with earth, depositing concrete, or brick- 
ing in; also against sagging, bulging, or running, when subjected to 
intense summer heat. The following means are adopted for this pur- 
pose: 

(1) On walls it is customary to protect the membrane with brickwork, or a 
facing of 1 : 3| Portland-cement mortar | to | in. thick. 

(2) On flat surfaces, the membrane is covered with concrete or bricks embedded 
in cement grout or a bituminous joint-filler (p. 382). 

(3) Where the membrane is laid on level floors of railroad bridges, very good 
results have been obtained by covering it with a 1^-in. layer of asphalt mastic 
flooring (p. 374) separated from the membrane by a course cf asphalt-saturated 
asbestos felt. 

Table XXXIII gives a resume of the damp-proofing and waterproofing methods 
applicable under different conditions to various structures. 



INSULATING AND SHEATHING PAPERS 

Insulating and sheathing papers are manufactured from special paper 
stock waterproofed with bituminous mixtures in one of three different 
ways, and according to which the following classes are recognized, viz.: 

(1) Paper coated but not saturated. 

(2) Paper saturated but not coated. 

(3) Paper both saturated and coated with bituminous compositions. 
The function of the insulating or sheathing paper is to prevent the 

transfer of heat from the outside to the inside of a closed chamber or 
building. Expressed in another way, its purpose is to keep the inside 
either cooler or warmer than the surrounding atmosphere. In the case 
of cold-storage plants, railroad refrigerator cars, ice chests or vaults, 
insulating papers are used to keep the interior cool; whereas with builds 
logs and residences heated artificially in winter, the function of the 
building or sheathing paper is to keep the interior wann, by preventing 
the egress of heat. 

Insulating and sheathing papers are used to line walls, floors, and 
sometimes ceilings in one or more layers. The greater the number of 
layers used, the more efficient the installation. For buildings and resi- 
dences, usually one layer of the paper is employed, whereas for cold- 

1 " Modern Methods of Waterproofing," by M. H. Lewis, N. Y., 1914. 



434 



ASPHALTS AND ALLIED SUBSTANCES 



TABLE XXXIII 
DESCRIPTION OF WATERPROOFING AND DAMP-PROOFING METHODS* 



No. 


Materials Employed. 


Method of Use. 


Thickness. 


Remarks 




Surface coatings: 








A 
B 


Clear damp-proofing 

paints. 
Paraffine melted and 


Brushed cold on exterior 

surfaces. 
Brushed hot on exterior sur- 


2 coats. 
Penetrates \ 


■j For damp-proofing new or 

old work above ground; 

\ also to preserve building 




applied hot. 


faces previously warmed. 


to ^ in. 


stone and prevent efilor- 
J escence. 


C 


Black damp-proofing 


Brushed cold on interior 


2 coats. 


Used to replace furring and 




paints. 


surfaces. 




lathing. 


D 


Bituminous cements. 


Trowelled cold on exterior 


1 coat, fs to 


Used for same purposes as 






or interior surfaces. 


^ in thick. 


black damp-proofing paints, 
also to a limited extent on 
outside of walls. 


E 


Bituminous adhesive 


Mopped hot on exterior sur- 


1 mopping, 


Used on outside of walls 




compounds. 


faces. 


fs to 1 in. 
thick. 


where conditions are not se- 
vere. 




Integral methods: 








F 


Cement-mortar with 


As a facing on interior sur- 


1 to 1 in. on 


Used as facings on new 




waterproofing com- 


faces exposed to mode- 


floors; 1 to 


work or to remedy defec- 




pound. 


rate or great heads of 


I in. on 


tive old work; also as 






water; also as a stucco on 


walls. 


stucco on new work. 






exterior walls. 






G 


Carefully graded con- 


Mixed in the body or mass 


Throughout 


Suitable only for new work 




crete with water- 


of the concrete when 


the con- 


in the course of construc- 




proofing compound. 


formed. 


crete. 


tion. 




Membrane method: 








H 


Bituminized fabrics 


In alternate layers on exte- 


2 to 10 lay- 


Suitable only for subgrade 




employed in con- 


rior surfaces exposed to a 


ers. 


work in the course of con- 




junction with bi- 


head of water. 




struction. 




tuminous adhesive 










compounds. 










Plastic method: 








I 


Asphalt mastic. 


As a plaster or coating on 


i to 1 in. 


Gives the best results on 






surfaces exposed to mode- 


thick. 


horizontal surfaces in new 






rate heads of water. 




or old work; difficult to 
apply on vertical surfaces. 




Membrane and plastic 










method: 








J 


Bituminized fabrics 


In alternate layers on sur- 


2 to 5 lay- 


Suitable only for new work. 




employed in con- 


faces exposed to moderate 


ers of fab- 


Capable of withstanding 




junction with as- 


or great heads of water. 


ric with a 


vibration. 




hpalt mastic. 




total of \ 
to 1 in. of 

mastic. 





* Waterproofing is intended to prevent the ingress or egress of water existing under pressure; 
damp-proofing is intended to resist the ingress of moisture in places where it cannot accumulate 
under pressure. 

storage plants, refrigerator cars, and ice chests it is customary to use 
two or more layers of the paper with air spaces in between. The 
least expensive and most efficient form of insulation consists in confining 



BITUMINIZED FABRICS 



435 



TABLE XXXIU— Continued. 
METHODS SUITABLE FOR VARIOUS STRUCTURES 



Nature of Work. 


During 

Construc- 
tion (New 
Work). 


After 
Construc- 
tion (Old 
Work). 


Remarks. 


Buildings: 




C, D 
A, B 

F 

D, E 
F, H, I 

F, H 
A, F 

F, G, H 
H, I, J 

F, G, H, I 
E, F, G 

F, G 


CD 
A, B 

A 
D, E 
F, I 

F 
A 


For damp-proofing walls and replac- 
ing furring and lathing. 

For damp-proofing and preserving 
stone and to prevent efflorescence. 

For waterproofing stucco and pre- 
venting cracks. 

For damp-proofing where appear- 
ance is immaterial. 

For preventing seepage or else to 
retain water. 

For resisting external water pressure. 

For damp-proofing and preventing 
cracks. 

For resisting water pressure or pre- 
venting seepage, and in certain 
cases to withstand vibration (ex- 
cept F). Great skill required to 






Exposed walls 


On outside. . . . 




On outside 


Superstructura 
toilets, lavor 
etc.), swimr 
indoors. 

Foundation pit 
ings, basemei 


floors Cin bath-rooms, 
atories, stables, garages, 
ning pools and tanks 

s, wells, trenches, foot- 
at walls and floors. 


Railroad struct^ 

Subways, tun 

and retaining 


ires: 

nels, arches, culverts 

; walls. 


F 

F 

F, I 




Water and sewage systems: 


For resisting water pressure. Mastic 
(I) difficult to instal when masonry 
once saturated with water. 

For preventing seepage of water or 
sewage through masonry. 

For protection against frost and the 
destructive action of sea water. 


Dams, conduits, filtering chambers, 
aqueducts, sewage disposal systems 
and manholes. 

Marine work: 

Concrete piles, piers, sea walls, and 
cement ships. 


F 
F 





a *' dead " or non-circulating air space between two or more layers of 
insulating paper. 

In practice, the paper is introduced in the floors, walls and parti- 
tions of buildings between protective layers of wooden boards. In 
other cases, the insulation is manufactured in the form of flat sheets 
composed of vegetable or animal fibres (e.g., flax, hair, etc.) sewn or 
otherwise fastened between two layers of bituminized paper, and known 
to the trade as " flax felt," '^ hair felt," etc. 

Untreated paper answers poorly for insulating purposes, as it will 



436 ASPHALTS AND ALLIED SUBSTANCES 

become affected by the moisture and dampness resulting from the 
condensation which occurs whenever a cool surface comes in contact 
with warmer air carrying a larger percentage of moisture. Under the 
influence of moisture, raw paper soon disintegrates and loses its 
value as an insulator. It is necessary, therefore, to waterproof the raw 
paper to enable it to satisfactorily, resist decay. Asphaltic materials 
and waxes are ordinarily employed for this purpose. 

Raw Paper Stock. A strong paper of open texture should be used 
for manufacturing insulating and sheathing papers. In accordance with 
the paper-makers' scale the raw stock is designated by a '' number," 
corresponding to the weight in pounds per ream composed of 500 
sheets, each measuring 2 by 3 ft.; in other words, by the weight in 
pounds of 3000 sq.ft. Raw papers from No. 30 to No. 180 are used, 
composed o? one or more of the following classes of fibres, viz.: 

(1) Jute, hemp and manila fibres. 

(2) Chemical wood fibres (sulphite and sulphate fibres). 

(3) Mechanical wood fibres (i.e., ground wood). 

(4) Rag fibres (cotton and wool). 

The first three classes are ordinarily used, and rag fibres in rare 
cases to open up the " texture " of the sheet, and enable it to 
saturate more readily.^ Rags serve to increase the " thickness factor " 
and correspondingly decrease the " strength factor " of the paper. 

Jute, hemp and manila fibres impart toughness, strength and permanence to the 
paper. Chemical wood fibres also tend to strengthen the paper, but are not regarded 
with as much favor as the foregoing, since it is difiBcult and in some cases impossible 
to remove the last traces of chemicals, which in time are apt to decompose and 
weaken the paper. Chemical wood fibres are divided into two classes, viz.: sul- 
phite and sulphate fibres respectively (p. 568). The sulphate fibres are present 
in '' kraft " papers, and represent one of the strongest of all fibres. Mechanical 
wood fibres are the first to " rot " and decrease in strength, and their proportion 
should therefore be kept as low as possible. 

In ascertaining the value of the raw paper for insulating and sheathing pur- 
poses, preference should be given to stock carrying the smallest percentage of 
mechanical wood. It u advisable that this should not exceed 25 per cent of the 
total. The balance may consist of jute, hemp, manila and chemical wood fibres in 
varying proportions, or chemical v/ood fibres alone. A good kraft paper will consist 
of 100 per cent chemical wood (sulphate) fibres. 

The paper should be loose in texture, showing a thickness factor of 0.090 to 
0.125 (p. 569), a strength factor (ascertained by the Mullen tester, p. 390) rang- 
ing from 0.35 to 1.00 (averaging about 0.60), and not exceeding 3 per cent ash on 
ignition. The highest strength factors are shown by kraft papers which are some- 
times guaranteed to test a pound on the Mullen tester, for each pound in weight on 
the paper-makers' scale. 

1 The addition of rag fibres rarely exceeds 25 per cent by weight. 



BltUMINIZED FABRICS 437 

Bituminous Saturations. For saturating the paper, the bituminous 
composition may consist of the following: 

(1) Dark-colored mixtures similar to those used for saturating 
prepared roofings (p. 391). 

(2) Light-colored mixtures containing one or more of the following prod- 
ucts: paraffine wax, petrolatum, viscous cylinder oils and wax tailings. 

Bituminous Coating Compositions. Dark-colored asphaltic mixtures 
are used, similar to the coatings of prepared roofings (p. 392), with the 
exception that they are usually manufactured harder in consistency and 
of a higher fusing-point. A small percentage of mineral, animal or vege- 
table wax (5 to 15 per cent) is sometimes added to impart wax-like 
properties and an " unctuous " feel.^ Residual asphalts have also been 
patented for coating purpo^^es.^ 

Method of Manufacture. The raw paper is saturated, coated, or 
both saturated and coated by a machine similar to that used for manu- 
facturing prepared roofings (p. 4C5). The web is saturated by running it 
through a tank of melted saturating material, usually heated by steam 
to a temperature of 225 to 350° F. As paper stock is considerably 
denser than roofing felt (the thickness factor amounting to y to i of the 
latter) it will carry a correspondingly smaller percentage by weight of 
saturation. A well-saturated paper should contain not less than 33 J 
per cent of bituminous saturation based on its finished weight. The 
greater the percentage of saturation present, the more moisture-resistant 
will the paper be. In rare cases the saturated paper will carry as high 
as 50 per cent by weight of bituminous saturation. 

f The coating is applied to the paper thinner than in the case of pre- 
pared roofings. It will range from 10 to 25 lb per 1000 sq.ft. (refer- 
ring to the coating on both sides of the sheet), when applied to satu- 
rated papers, with an increase of about 25 per cent for papers which 
are coated but not saturated. 

Insulating and sheathing papers are sold in roUs containing 1000, 500 and in 
some cases 250 sq.ft. There are no standard weights recognized by the trade, each 
manufacturer following his own views. Papers are marketed at the present time 
from 20-125 lb. per 1000 sq.ft., the heavy weights falHng on the border-hne between 
papers and " felts," often containing a proportion of rag stock. 

Efficiency of the Paper .The efficiency of the finished product is 
dependent upon the following features: 

(1) Weight per unit area. 

(2) Mullen strength at 77° F. 

(3) Resistance to moisture. 

lU. S. Pat. 426,633 of Apr. 29, 1880 to H. J. Bird. 

2 u. s. Pat. 378,520 of Feb. 28, 1888, T. J. Pearce and M. W. Beardsley. 



438 



ASPHALTS AND ALLIED SUBSTANCES 



It is a peculiar fact that the tensile strength of the paper will gradually increase 
after manufacture at first rapidly and then more slowly as the paper seasons. Sat- 
urated and coated papers are more waterproof, more durable and better insulators 
than the other types. Similarly, a paper which is saturated is more efficient than one 
which is simply coated. The several methods of waterproofing are designed to meet 
the prevailing views of engineers, some preferring one and some another. Sometimes 
the purpose for which the paper is to be employed will predetermine the type used; 
for example, for surfacing sheets of fibrous material (flax-felt or hair-felt), saturated 
papers only can be employed, since coated papers would gum up the needle of the 
machine used for sewing the sheets together. 

The moisture-resistant properties of an insulating paper may be ascertained by 
weighing and finding the Mullen strength of a sheet of predetermined area before 
and after immersion in water for forty-eight hours. A square foot of the paper is 
ordinarily employed for this purpose. Well-known brands of paper tested by the 
author showed the following results: 





Saturated 


Saturated 


, Saturated 


Saturated 


Saturated 




Only. 


Only. 


and Coated. 


and Coated. 


and Coated. 


Originally: 


A 


B 


C 


D 


E 


Pounds per 1000 sq.ft 


82.2 


78.9 


43.3 


61.0 


101.0 


Percentage of asphalt 


45.0 


23.2 


55.0 


53.0 


52.0 


Mullen strength in pounds. 


58.1 


58.8 


31.8 


47.1 


60.3 


After immersion: 












Gain in weight per cent. . . 


32.0 


49.7 


27.5 


23.0 


26.5 


Loss in strength per cent. . 


54.7 


71.7 


51.5 


.54.0 


55.5 



Papers A and B originally weighed almost the same, but the gain in weight and 
loss in strength are very much less in A, due to the larger percentage of asphalt 
carried by the paper. 

The thicker the paper, the stronger and more durable it will prove to be. How- 
ever, from the standpoint of insulation it is better to use two layers of a thin paper 
with an air space in between, than a single layer of thick paper equal to their 
combined thickness. 

Saturated and Coated Papers for Electrical Insulation. Sometimes 
papers of this construction are used for electrical insulating purposes, as 
for example in constructing automatic telephone switchboards for wrap- 
ping wires and cables, etc. The following tests were obtained by the 
author upon subjecting papers of this character to an alternating cur- 
rent increased at the rate of 125 volts per minute between flat disc ter- 
minals with rounded edges, the areas of contact measuring exactly 1 sq.in. : 



Weight in pounds per 1000 sq.ft 

Thickness in mils 

Mullen strength at 77° F 

Breakdown voltage at 77° F 

Volts per mil 



21 
5 

25.0 
750 
150 



42 

8 

30.0 

1190 

149 



60 
12 

40.2 
1637 
lo7 



90 
20 

72.2 
2650 
132 



BITUMINIZED FABRICS 439 



ELECTRICAL INSULATING TAPE 

Bituminized tapes for electrical insulating purposes are prepared 
by passing strips of cotton or muslin through a bath of melted bituminous 
material intended to fill the pores of the fabric and provide a slight excess 
on the surface. They are manufactured in widths of |, f, and 1 in. re- 
spectively, and wound in | to |-lb. rolls, averaging J lb. The length per 
pound varies from 62 to 72 hneal yards for ^J-in. tape, 40 to 50 yards 
for |-in. tape and 31 to 36 yards for 1-in. tape. The thickness will range 
from 0.015 to 0.025 in., averaging 0.020 in. 

A sheet of cotton cloth weighing from 4 to 6 oz. per square yard 
is passed through a bath of melted bituminous composition, so that an 
excess will adhere to the surfaces (from 0.005 to 0.007 in. to both sides 
of the sheet) and after cooling, is torn into strips of the desired width 
and wound into rolls of predetermined weight. The weight of the prod- 
uct should average 1 lb. per square yard, carrying about 0.33 lb. of 
cotton fabric and 0.67 lb. of bituminous saturation and coating. 

Characteristics of the Bituminous Impregnation. The bituminous 
composition with which the fabric is treated may consist of one or more 
of the following products: 

Pure native asphalts, residual asphalts, blown petroleum asphalts, 
wurtzilite asphalt and fatty-acid pitch, used either singly or in various 
combinations when of the required consistency; or else if too hard (and 
the same applies also to asphaltites) fluxed to grade with one or more 
of the following, viz.: soft native asphalt, residual oil, soft residual 
asphalt, soft blown petroleum asphalt, soft fatty-acid pitch, animal and 
vegetable oils and fats, and wool grease. 

It should comply with the following tests: 

(1) The consistency at 77° F. should be below 7.0 (Test 9c). 

(2) The susceptibility factor (Test 96) should be as low as possible, and prefer- 
ably under 25. 

(3) The ductility at 77° F. should be as high as possible, and preferably over 25 
centimeters (Test 106). 

(4) The fusing-point by the K. and S. method (Test 15a) should be between 
80 and 100° F. 

(5) The volatile matter at 500° F. in four hours (Test 16a) should not exceed 
5.0 per cent. 

(6) It should appear " tacky " and adhesive at room temperature, and retain 
this property as long as possible on exposure to air. A strip of tape hung indoors 
and protected from the direct rays of the sun should show no dimunition in tacki- 
ness at the end of two months. This is important, for if the tape once dries out, 
it becomes valueless. 



440 ASPHALTS AND ALLIED SUBSTANCES 

According to the Navy Department's specifications for insulating tape issued 
July 11, 1910 (No. 17-T-l) the finished product should comply with the following 
requirements : 

The surface must be smooth, the body entirely free from holes, the edges straight 
without ravelUng, and the width uniform. When unwinding from the original coil, 
there must be no tendency to leave a thread sticking to the next layer. When 
held before a strong light, there must be no evidence of pin holes. The cotton to 
be well saturated but the compound must not be put on in excess. The separation 
under a pull of 2 lb. per inch width applied to a coil rewound on a |-in. mandrel, 
under a tension of 10 lb. at 75° F. shall not exceed 8 in. per minute. A strip 
exposed to dry heat of 210° F. for sixteen hours shall show a separation of not 
exceeding 3 in. per minute at 75° F. under a tension of 2 oz. per inch width, when 
wound in a coil on a |-in. mandrel immediately after removal from the source of 
heat. The weight of the compound applied to the fabric shall be about 0.65 lb. 
per square yard. The ash on burning shall not exceed 45 per cent. The tensile 
strength at 75° F. shall not be less then 40 lb. per inch of width, when performed 
on a rubber testing machine, the initial distance between the clamps being 3 in., 
and the rate of separation 3 in. per minute. The dielectric strength shall not be 
less than 1000 volts per millimeter thickness (5 minims). No breakdown shall 
result between two brass balls 2 cm. in diameter, at the specified alternating poten- 
tial having an effective value at a frequency of 60 cycles, applied continuously for 
five minutes. In making the test the electrodes must be brought close together 
so that the tape will just move between them. The tape shall be packed in tissue 
paper or tin foil and enclosed in a tin box, to prevent it from drying out. 



BITUMINIZED WALL BOARD 

Methods of Manufacture. Wall board is used in forming ceilings, 
also partitions between the rooms of dwellings. It is nailed directly to 
the wooden beams and takes the place of lath and plaster. Wall board 
is manufactured by assembling two or more layers of pulp board (manu- 
factured from ground wood) or chip board (manufactured from waste 
papers), so as to form a total thickness approximating J in. The 
individual layers of pulp or chip board measuring 0.025 to 0.060 in. arc 
generally cemented together with silicate of soda, but in certain cases 
asphalt is used. The manufacturers contend that asphalt contributes 
to the moisture-resisting properties of the finished board, but this, how- 
ever, is a mooted question. When asphalt is used, it is introduced while 
melted between the several layers of pulp or chip board, following sub- 
stantially the same procedure as in manufacturing multiple-layered 
roofings (p. 410). 

Each asphalt layer varies from 0.020-0.025 in. thick. Theoretically, an asphalt 
having a specific gravity of 1.00 at 77° F. should weigh 5.20 lb. per 1000 sq.ft. in a 
layer 0.001 in. thick. Actually, however, it will weigh 4.80-4.85 lb., due to the fact 



BITUMINIZED FABRICS 441 

that a portion of the asphalt soaks into the board on account of its porosity and 
sHght irregularities in its surface. 

Another type of bituminized wall board consists of a single layer of chip board 
measuring about 0.060 in. thick, surfaced on one side with a fairly heavy coating 
of asphalt, in which are embedded wooden lath strips, spaced at intervals.^ This 
may either be used as a wall board by fastening it with the smooth side outward, 
or if reversed, it may be used as a plaster board, and plaster applied directly to the 
lath strips. Still another modification consists of wooden lath strips coated with 
asphalt and assembled side by side between two layers of strong paper or chip 
board firmly cemented in place with asphalt. ^ 

1 U. S. Pat. 868,157 of Aug. 15, 1907 to G. F. Bishopric. 
2U. S. Pat. 200,850 of Aug. 13, 1878 to D. S. Armstrong. 



CHAPTER XXVI 

SEMI-LIQUID, SEMI-SOLID AND SOLID BITUMmOUS 
COMPOSITIONS 

Adhesive Compounds for Built-up Roofing and Waterproofing Work. 

Tar-pitches and asphaltic products are used for this purpose, similar 
in composition to the surface coatings of sheet roofings (p. 392). Adhe- 
sive compounds are employed in three classes of work, viz.: 

(1) For constructing membrane waterproofings on underground work 
exposed to uniformly moderate temperature conditions, as for example 
tunnels, foundations of buildings, retaining walls, etc. 

(2) For constructing membrane waterproofings on structures above 
ground, exposed to wide fluctuations in temperature and subjected to 
severe vibration, as on bridges, culverts, etc. 

(3) For constructing built-up roofs exposed to extremely wide fluctu- 
ations in temperature, and to little or no vibration. 

Each class will be considered separately. 

Adhesive Compounds jor Membrane Waterproofing Underground. 
Since these are exposed to uniformly moderate temperature conditions, 
they are usually prepared of a comparatively low fusing-point. The 
two most important considerations are that they should have a high 
tensile strength and great ductility at 77° F., and it is immaterial whether 
or not they have a low susceptibility factor. 

The proposed tentative specifications for coal-tar pitch recommended by the 
American Society for Testing Materials, (1917) for waterproofing under moderately 
miiform temperature conditions (Type A) are as follows: 

(a) The fusing-point as determined by the cube method in a water bath shall 
be between 120-140° F. In specifying the fusing-point within the above limits, a 
variation of not more than 5° F. in either direction will be permitted. 

(6) The penetration at 77° F. shall not be less than 20 nor more than 120. 

(c) The ductility at 77° F. when a briquette having a minimum section of 1 
sq.cm. is pulled apart at the rate of 5 cms. per minute, shall not be less than 40 
cms. 

{d) The loss of a 20-gram sample on heating five hours at 325° F. shall rot 
exceed 9 per cent for pitch having a fusing-point between 120 and 130° F., or 7 
per cent for pitch having a fusing-point between 130 and 140° F. 

442 



BITUMINOUS COMPOSITIONS 443 

(e) The specific gravity at 77/77 F. shall fall within the range of 1.24 and 1.34. 
The specific gravity at 140/140° F. of the distillate to 671° F. shall not be less than 
1.06. 

(/) The matter soluble in hot toluol-benzol shall not be less than 65 or more 
than 85 per cent. 

(g) The ash shall not exceed 1 per cent. 

The proposed tentative specifications for asphalt recommended by the same 
Society (1917), are as follows: 

(a) The fusing-point shall be between 100 and 140° F. as determined by the 
ball and ring method in a water bath, and shall be specified for one of the following 
classes: 130-140° F.; 115°-130F.; 100-115° F. 

(b) The penetration at 77° F. shall not be less than 15 nor more than 125, and 
shall bear the following relation to the fusing-point: 

Penetration range of 50-75 for fusing-points between 130-140° F. 
Penetration range of 75-100 for fusing-points between 115-130° F. 
Penetration range of 100-125 for fusing-points between 100-115° F. 

(c) The ductility at 77° F. shall not be less than 30 cms. 

(d) The specific gravity at 77/77° F., shall not be more than 1.08. 

(e) The solubility in cold carbon disulphide shall not be less than 95 per cent. 
(/) The loss of a 50-gram sample on heating five hours at 325° F. shall not 

exceed 1 per cent, and the penetration of the residue shall not be less than 50 per 
cent of the original penetration. 

(g) The ash shall not exceed 4 per cent. 

The specifications issued by the Public Service Commission of the State of New 
York for asphaltic adhesive to be used in subway construction, provides for smaller 
ranges in the tests, viz.: 

(a) Not less than 95 per cent shall be soluble in cold carbon disulphide. 
(6) At least 98| per cent of the portion soluble in cold carbon disulphide shall 
be soluble in cold carbon tetrachloride. 

(c) The flash-point shall not be below 350° F. when tested in the New York 
State closed tester. 

(d) When 20 grams are heated for five hours at 325° F. in a tin box 2^ in. in 
diameter, the loss shall not exceed 5 per cent by weight, nor shall the penetration 
at 77° F. after such heating be less than one-half the original penetration. 

(e) The fusing-point by the K. and S. method shall be between 115 and 135° F. 
(/) The penetration at 77° F. shall be between 75 and 100. 

{g) The ductihty at 77° F. shall not be less than 20 cms. 

Adhesive Compounds for Membrane Waterproofing above Ground. 
Bituminous materials used under these conditions must necessarily 
withstand wide variations in temperature without softening or becoming 
brittle. In other words, the material should have a low susceptibility 
factor. This will necessarily exclude tar products, and restrict the 
choice to the following asphaltic compositions: 



444 ASPHALTS AND ALLIED SUBSTANCES 

(1) Asphaltites fluxed to the desired consistency with residual oil, petroleum 
asphalt or soft residual asphalt. 

(2) Blown petroleum asphalts of the proper consistency. 

No " standard " specifications have at present been proposed for this class of 
work, but in general the adhesive should comply with the following characteristics: 

(a) The penetration. (Test 96) shall range as follows: 

At 115° F 100-150 

At 77° F 50-100 

At 32° F 25-50 

(b) The susceptibility factor shall not exceed 35 (Test 9dy 

(c) The ductility at 77° F. (Test 10a) shall not be less than 20. 

(d) The fusing-point by the K. and S. method (Test 15a) should be between 
125-155° F. 

(e) The volatile matter at 325° F. for five hours (Test 16a) should be less than 
1 per cent. 

(/) The flash-point (Test 17a) should exceed 450° F. 

(g) Solubility in carbon disulphide (Test 21a) to exceed 95 per cent. 

(h) Solubihty in 88° naphtha (Test 23) to be greater than 80 per cent. 

Adhesive compounds may be safely heated to 400° F. when applied to the 
masonry or felt. A typical product of this group is represented by the specimen 
of blown petroleum asphalt derived from Mexican crude oil having a fusing-point 
of 143° F. (K. and S. method), included in Table XXV, facing p. 294. 

Adhesive Compounds for Built-up Roofing Work. This class may 
either consist of coal-tar or asphaltic products as they are used in 
structures where there is little to no vibration. The same materials 
are adapted for this purpose as for the coating compounds of prepared 
roofings but they are generally prepared of a softer consistency and 
lower fusing-point. The susceptibility factor does not play an impor- 
tant role, and the ductility may be considerably less than in the fore- 
going class of adhesives. No standard specifications have been pro- 
posed for this group of products, but the author's experience dictates 
the following ranges: 

(a) Penetration at 77° F. (Test 96) to be between 25-75. 

(6) The consistency at 77° F. (Test 9c) to be between 10 and 25. 

(c) The ductility at 77° F. (Test 10a) to be not less than 10 cms. 

(d) The tensile strength at 77° F. to be not less than 2.0. 

(e) The fusing-point of coal-tar products by the cube method (Test 15c) to 
range between 145 and 175° F. 

(/) The fusing-point of asphaltic products by the ball and ring method (Test 
156) to range between 160 and 190° F. 

1 The following tests have been suggested to insure sufficient pliability at low temperatures, also 
resistance to the heat of the sun: a prism g in. XI in. X3 in. when reduced to 0° F. in a mixture of 
enow and salt must remain pliable, and a 2-in. cube must not flow or become distorted when sub- 
jected to 110° F. for 10 hours. 



BITUMINOUS COMPOSITIONS 445 

(g) The volatile matter at 325° F. in five hours (Test 16a) shall not exceed 
1 per cent, and the penetration of the residue at 77° F. to be not less than 50 per 
cent of the original penetration. 

(h) The flash-point (Test 17a) to exceed 350° F. 

(i) The solubility of asphaltic products to exceed 95 per cent in carbon disul- 
phide (Test 21a) and 75 per cent in 88° naphtha (Test 23). The solubihty of coal- 
tar products in hot toluol-benzol (Test 22) to range between 65 and 85 per cent. 

Compounds for roofing work are usually applied at temperature of 350-4C0° F. 

Pipe-dips and Pipe-sealing Ccirpounds. Pipe Dips. To prolong 
the life of metal pipes, it is scmetimes customarj^ to treat them with 
solid bituminous compositions ^ to protect them either inside or outside 
or both. The treatment may consist in simply dipping the pipe in the 
melted compound, a combination of dipping and wrapping with a 
bituminized fabric or burying the entire pipe in a trough filled with 
bituminous matter.^ Steel pipes are more susceptible to corrosion than 
cast-iron pipes, since the minute particles of graphitic carbon or eke the 
molecular structure of the cast iron tends to retard its action. Pipes 
are prone to corrode internally when used for conveying water, includ- 
ing water-mains or w^ater-supply pipes. The external corrosion is 
brought about by one or more of the following circumstances: 

(1) Exposure to moist soil conditions. 

(2) Electrolysis induced by stray electric currents. 

(3) Exposure to mineral salts in the soil, as for example the " alkali " 
normally occurring in some of the western States. 

(4) Contact with dilute acid, as for example sulphuric acid occurring 
in the water of coal and other mines, and derived from the sulphur 
present in the minerals (sulphides, sulphates, etc.). 

Cast-iron pipes are rarely protected at the present time, but steel 
pipes are often coated, and especially when used for the following pur- 
poses, viz.: water mains, lines for conveying oil across the continent, 
steel flumes for irrigation or powder purposes, compressed-air pipes for 
operating block signals or swdtches on raihvays, conduits for transmis- 
sion and telephone wires, pipes for conveying illuminating or natural 
gas, pipes apt to come in contact with acid liquors in mines, etc. 

To fulfil its function satisfactorily, a covering should be:-^ 

(1) Impervious to air and moistiire, and a non-conductor of electricity. 

1 Licseed oil and bituminous paints, p. 472, also inorganic materials such as alloys, oxides, 
silicates, and Portland-cement mortar or concrete are also used for this purpose. 

2 " Rrstless Coatings" by M. P. W^ood, 1st Edition, New York, 1904, Chapter XII; "The 
Industrial and Artistic Technology of Paint and Varnish," by A. H. Sabin, 2d Edition, New York, 
1917, Chapter XVIII; Series of articles by R. B. Harper entitled " The Comparative \'ali:es ci 
Various Coatings and Coverings for the Prevention of Soil and Electrolytic Corrosion of Ircr. 
Pipe," Am. Gas Light J., 91, 429, 475, 528, 575, 625 and 667, 1909. 

3 " The Corrosion of Metals," A. H. Sexton, Manchester, England, 1905, 



446 ASPHALTS AND ALLIED SUBSTANCES 

(2) Of such a character that should the surface be broken through, the covering 
will not accelerate corrosion. 

(3) Not susceptible to being chipped or broken through by any treatment 
which the pipe may receive during its installation or use. 

(4) Durable without becoming porous, brittle or cracking by the action of air, 
moisture or light under the conditions to which it is likely to be exposed. 

(5) Incapable of producing any deterioration in the metal to which it is applied. 

(6) Easy of appHcation. 

(7) Easily renewable, if the surface becomes broken or damaged by accident or 
otherwise. 

The jSrst compound to be used for this purpose was composed of moderately 
hard coal-tar pitch combined with linseed oil.^ The pipe to be treated was brought 
to a temperature of 300° F., and then immersed into a bath of the pitch mixture 
maintained at the same temperature. The pipe upon being removed was kept at 
300° F., and protected from draughts until the coating baked hard and tough. 
Pipes treated in this manner are said to have proven very durable. 

Modern practice is very similar to that followed by Smith, but when coal-tar 
pitch is used the linseed oil is replaced with creosote oil (i.e., dead or anthracene oil), 
of which small quantities are added from time to time, to maintain the pitch at the 
proper fusing-point and hardness, since continuous heating would otherwise volatiHze 
the light oils, and gradually harden the coal-tar pitch. Under the most favorable 
conditions, however, coal-tar pitch and creosote oil form a brittle coating which is 
apt to be injured and chip or scale off in time. For these reasons asphaltic com- 
positions are being used in place of the coal-tar pitch, and generally with better 
results. 

The most satisfactory asphaltic compounds correspond in physical properties 
with the adhesive compounds used for waterproofing railroad bridges (p. 443), 
having a low susceptibility factor, moderately highfusing-point, moderate hardness, 
great toughness, elasticity and adhesive properties. Residual oil is generally used to 
keep the asphalt fluxed to a uniform hardness and fusing-point. 

The bituminous mixture is maintained at about 400° F., in a horizontal or verti- 
cal tank, well insulated to prevent radiation, and heated by coal, oil or producer 
gas. The sections of pipe are first placed in an oven through which is circulated 
a current of air heated to 400° F., then immersed into the bath of melted bituminous 
matter, allowed to drain in a heated chamber above the tank and finally cooled. The 
finished coating is 0.05-1.10 in. thick, and because of the "baking" to which it 
has been subjected, its fusing-point becomes a good deal higher than the compound 
originally placed in the tank. 

The great objection to the use of a dipped coating is the ease with which it 
becomes injured on handling during transportation or installation. This objection 
may be overcome by wrapping the pipe spirally after it has been dipped with strips 
of bituminized fabric, such as tar- or asphalt-saturated paper, felt or cloth 0.005- 
0.100 in. thick (measuring 10-15 sq.ft. per pound). For wrapping. 2-in. pipes, 
8-in. strips are used; for 4-in. pipes, 16-in. strips; and for 8-in. pipes, 32-in. strips. 
The fabric may be fastened to the dipped coating by the agency of thin layer of 
melted bituminous composition, or the cold application of a paint composed of the 
composition dissolved in a volatile solvent. The pipe after bein^ wrapped may 
either be marketed as such or else surfaced with another such coating. Pipes finished 

»Eng. Pat. of 1848, No. 12,291, Oct. 19, to R. Angus Smith. 



BITUMINOUS COMPOSITIONS 447 

in this manner are much less susceptible to injury, and will last for many years 
even when subjected to severe conditions. 

Pipe-sealing Compounds. Bituminous compounds have also met with 
considerable success for sealing the joints of metal or earthenware sewer 
and drain pipes. Asphaltic compounds are usually used for this purpose, 
carrying 50 to 65 per cent of finely divided mineral matter, preferably 
silica on account of its resistance to acids and other corrosive agencies. 

The pipes may be assembled underground in a trench or pipe gal- 
lery, and the bituminous composition melted at a temperature of 350 
to 400° F. poured into the joints, which should first be well caulked 
to hold the compound in place. Sometimes two or more sections of the 
pipe are joined together above ground, while they are maintained in a 
vertical position, and when the compound cools they are coupled to 
additional lengths below ground. This will save time, since it is easier 
to form the joints while in a vertical position, than when laid horizon- 
tally. 

The following specifications apply to a well-known pipe-seal compound on the 
market : 

(Test 7) Specific gravity at 77° F 1 . 50 to 1 . 75 

(Test 9c) Consistency at 77° F 10 to 15 

(Test 106) Ductility at 77° F Greater than 1 . 

(Test 11) Tensile strength at 77° F Greater than 10.0 

(Test 15a) Fusing-point (K. and S. method) 185-200° F. 

(Test 16a) Volatile matter at 500° F. in 4 hrs Less than 1.5% 

The principal considerations are that the compound should possess a high fusing- 
point so as not to soften in warm weather or on coming in contact with hot water 
flowing through the pipe; it should be sufficiently ductile to permit the pipe settling 
in sections without the joints breaking open; and it should have great adherence 
and tensile strength to enable the line to expand or contract without tearing away 
the compound from the pipe. 

The advantage in using bituminous compounds for sealing joints is because they 
will permit the pipe to settle, as it is very apt to do in a freshly filled trench, without 
danger of the joints opening. In addition, they prevent the roots of trees or shrubs 
working their way into the joints, and congesting the inside of the pipe line. Other 
materials used for this purpose, such as cement mortar, sulphur, etc., possess these 
defects. 

Electrical Insulating Compounds. Bituminous compounds adapt 
themselves very well for electrical insulating purposes, on account of 
their high breakdown voltage, resistance to moisture, acids, alkalies and 
changes in temperature, also because they are in most cases capable 
of withstanding exposure to the weather. 

A review of the patent literature reveals thousands of patents in 
the electrical industry involving the use of bituminous materials and for 



448 ASPHALTS AND ALLIED SUBSTANCES 

hundreds of different purposes. The scope of this book will permit a 
brief survey of but the most important principles involved. 

Semi-solid to solid bituminous compounds capable of melting under 
the action of heat are combined in many ways, often with the addition 
of other substances, including resins; rubber; animal and vegetable oils 
and fats; animal, vegetable and mineral waxes; mineral fillers; sulphur, 
etc. The electrical resistance of bituminous compounds varies from 200 
to 1200 volts per mil, ascertained by subjecting a specimen at 77° 
F. between two spherical terminals, 2 cms. in diameter, to an alternat- 
ing current of 60 cycles, the voltage being increased at the uniform speed 
of 600 volts per minute, until a break-down occurs. 

The following figures show the volume resistivity of soHd bituminous and other 
dielectrics, expressed in ohm-centimeters, in the order of decreasing values: ^ 

Speeial paraffine Over 500 XlQie 

Ceresin Over 500X10>6 

Hard rubber lOOXlQie 

Asphalt (medium hard) 50 XIO^^ 

Sulphur 100 X1015 

Rosin 50 XlOis 

Chlorinated wax (" halowax ") 20X1015 

Shellac 10 XlO^s 

Glass 8 X1015 

Yellow wax 2X10i5 

Mica (brown African clear) 2 XIO^^ 

Unglazed porcelain 3 XIO^* 

Tetrachlornaphthalene 50 XIO12 

Mica (India ruby stained) 50 XIO12 

Paraffined mahogany 40 XIO^^ 

Italian marble 100 X109 

White celluloid 20 XIO^ 

Slate 100X106 

Insulation for Cotton-covered Transmission Wires. The cotton cov- 
ering is either saturated with a bituminous mixture, or both saturated 
and coated therewith. The saturation is similar to that used for im- 
pregnating prepared roofings (p. 391). Asphaltic products of a harder 
consistency, corresponding to the weather-coatings of prepared roofings, 
are employed for coating cotton-covered wires exposed out-of-doors, such 
as electric light wires. Wax-like properties are often imparted to the 
coating by incorporating a small percentage of animal, mineral or vege- 
table wax. Rubber is scarcely ever used as an ingredient of out-of-door 
mixtures because of its inferior weather-resisting properties, but it may 
be used to good advantage for covering cotton-covered wires indoors, 
in which event the bituminous matter should properly be regarded as an 
adulterant of the rubber. If the bituminous matter is not present to 

' Scientific Paper No. 23-1 of the Bvreau of Standards, Wash., D. C, 1915, " Insulative Proper- 
tics of Solid Dielectrics," by H. L, Curtig, 



BITUMINOUS COMPOSITIONS 449 

excess, the mixture will largely retain the physical properties of rubber, 
and may be vulcanized by incorporating a small percentage of sulphur. 

Bare copper wires may be insulated with certain varieties of fatty-acid pitch, 
which are transformed into an insoluble and infusible coating by heating to a high 
temperature (p. 332). 

Vacuum Impregnating Compounds. These are used for insulating 
the held and armature windings of motors and dynamos, also magnet 
and transformer coils. The copper wire loops are wound with muslin, 
or in some cases with asbestos, and then impregnated with a melted 
bituminous or oleo-resinous composition. The former only falls within 
the scope of this treatise, and includes asphaltic products com,posed sub- 
stantially of the same materials, and having approximately the same 
physical properties as the surface coatings of prepared roofings (p. 392). 
The following characteristics are of importance: 

(1) The mixture should melt to a liquid having the lowest possible viscosity 
(Test 8a) at the temperature at which it is maintained while impregnating the coils. 
Since the purpose of the compound is to penetrate the mushn wrapping of the wire, 
it follows that the more hquid the melted compound, the more thoroughly it '^i\\ 
fulfil this function. 

(2) The softer the compound for the prescribed fusing-point, the less it is apt to 
crack in service, especially as the revolving armature of a motor or dynamo is sub- 
jected to the most extreme conditions in regard to vibration. Shoiild the compound 
crack or powder, its insulative value will be nullified, and the machine will become 
short-circuited and put out of commission. The mixture should preferably have a 
penetration of 75 to 125 at 77° F. (Test 96). Its susceptibihty factor should also 
be as low as possible, and under no circumstances in excess of 25 (Test 96). 

(3) The ductility at 77° F. should be as high as possible, and preferably greater 
than 5 (Test 10). 

(4) The fusing-point by the K. and S. method (Test loa) should exceed 180° F. 
This will insure the compound remaining in place when the machine heats up in 
service. 

(5) The volatile matter should not exceed 2 per cent at 500° F. in four hours 
(Test 16a). 

(6) The solubility in carbon disulphide (Test 21a) should exceed 99 per cent. 
Mineral or carbonaceous matters will interfere with the penetrating properties of the 
compound. 

Residual oil is ordinaril}' used to flux the compound to its original consistency, 
if the hardness or fusing-point increases while maintained in the liquid condition. 

The apparatus consists of two steam-heated, air-tight iron tanks, one for carry- 
ing the coils to be treated, and the other for storing the melted compound, as 
illustrated in Fig. 149. The coils are placed in the impregnating chamber, the heat 
turned on and the air exhausted by the pump within |-2 in. of the barom.eter, 
which draws out all the moisture. In the meantime the compound is melted in 
the steam-heated liquor tank at 300° F., whereupon it is allowed to enter the vacuum 
chamber and subjected to a pressure of 90 lb. per square inch which forces it 



450 



ASPHALTS AND ALLIED SUBSTANCES 



throughout all parts of the coil. It is maintained under compression for one or 
more hours, when the valve between the tanks is opened, the compound forced back 
into the liquor tank, and the excess allowed to drain from the coils upon being 
subjected to a dry heat for half an hour, which also completes the saturation. It 
is claimed that coils treated by this process give better service than those insulated 
by varnish (see p. 478), and moreover, since they become practically solid, there is 
no danger of the wires slipping. The total cost of treatment is less than when 
varnishes are used, but to offset this, the equipment is more expensive. The units 
are made with impregnating and compound storage tanks measuring 108 in. diam- 
eter by 240 in. high as a maximum. 

Transformer and magnet coils may be treated in the same manner, and tests 
made in the author's laboratory demonstrate that tightly wound coils several inches 



COrlPWCSSOff 




Courtesy of J. P. Devine Co. 

Fig. 149. — Vacuum Impregnating Apparatus. 

thick, composed of high gauge wire may be thoroughly impregnated. Bituminous 
compounds should only be used for air-cooled transformer coils, as they will become 
softened and dissolved in oil-immersion transformers. The method is now being 
used almost universally in large plants. 

Wooden pipes for conveying liquids, wooden storage battery boxes, cotton belt- 
ing, etc., may be impregnated with bituminous compositions in an apparatus of 
this type. 



Junction-box and Pot-head Compounds. These are used for filling 
the metal receptacles in underground electrical transmission lines, where 
feeders branch off from the main wires. The connections are usually 
made inside of a metal box known as a '^ junction box " or '' pot-head." 
Asphaltic compounds fusing in the neighborhood of 200° F. (K. and S. 
method, Test 15a) are melted and poured into the receptacle to her- 



BITUMINOUS COMPOSITIONS 451 

metically seal the wires after the junction or connection has been 
effected. 

Battery-box Compounds. These are used for seahng '' dry " batter- 
ies. After the zinc container is filled with chemicals in paste form, and 
the rod of carbon introduced, the top is hermetically sealed with the 
" battery-box compound." This consists of moderately hard coal-tar 
pitch (fusing at 160 to 170° F. by the cube method, Test 15c) combined 
with about an equal weight of siliceous filler. 

" Carbons " for Batteries, Electric Lights and Armature Brushes. 
" Carbons " for the electrical industry are formed by heating a mixture 
of powdered coke and hard coal-tar pitch (fusing above 200° F. by the 
cube method, Test 15c), in a closed metal mould. Upon subjecting this 
mixture to a red heat, the coal-tar pitch carbonizes, and consolidates 
the particles of coke-carbon. Armature carbons are often mixed with a 
proportion of graphite to reduce their friction against the rapidly revolv- 
ing armature; and electric light carbons with a proportion of mineral 
constituents (usually less than 20 per cent) including the rare earth 
oxides, silicates, fluorides, borates, etc., to increase the luminosity or 
modify the color of the electric arc. 

Bituminous Rubber SubstituteSo On account of the high price of 
pure rubber, it is often adulterated with fusible materials derived from 
the animal, vegetable or mineral kingdoms. Resins, animal or vege- 
table oils and fats, animal and vegetable waxes have been used largely 
for this purpose. Bituminous compounds have also found a ready use, 
including the following groups: 

(1) Ozokerite and paraffine wax. 

(2) Hard native asphalts. 

(3) Asphaltites either used alone or fluxed. 

(4) Blown petroleum asphalt. 

(5) Wurtzilite asphalt. 

(6) Rosin pitch. 

(7) Fatty-acid pitches. 

(8) Special products including chlorinated naphthalene, etc. 

The bituminous materials are regarded mainly as " extenders," dilu- 
ents or cheapeners, although in som.e cases they are purposely used to 
soften the rubber, and in others to increase its weather-resisting proper- 
ties. These substitutes, known as " mineral rubber " or " factis " are 
incorporated with the raw rubber on the masticating rollers (consisting 
of heavy steel rollers revolving at unequal speeds, capable of being 
heated or cooled by steam or water). One method consists in first 



452 ASPHALTS AND ALLIED SUBSTANCES 

combining the substitute with reclaimed rubber and mineral fillers on 
the rolls. The raw rubber is then masticated a short time, whereupon 
the bituminous mixture, still warm from the masticating process, is 
gradually worked in, small quantities at a time, and the composition 
finally vulcanized in the usual manner. 

The most satisfactory bituminous materials for this purpose include: 

(1) Products which of themselves possess " rubber-like " properties (including a 
certain degree of toughness, resilience, tenacity and ductility), as for example 
gilsonite combinations, wurtzilite asphalt, blown petroleum asphalts, and certain 
of the fatty-acid pitches. 

(2) Bituminous substances which are capable of being hardened and toughened 
by the sulphur used in the vulcanization process. To this class belong the gilsonite 
combinations, wurtzilite asphalt and fatty-acid pitches. 

Acccrding to the well-known, and often quoted experiment by Heinzerling and 
Pahl,^ the use of certain bituminous materials actually im,proves the elasticity and 
insulative properties of the rubber when added in small percentages, although at 
best they tend to decrease the tensile strength. 

The harder waxes and bituminous materials are used in mixtures of hard rubber 
(ebonite), and the softer waxes and bituminous materials in soft rubber composi- 
tions. Sometimes the bituminous product is partially vulcanized with sulphur 
before it is combined with the rubber, especially when ^oo soft to be used without 
further treatment. 

Moulding Compositions. Mixtures for Small Moulded Articles. For- 
merly shellac was extensively employed for manufacturing small moulded 
articles used for electrical fittings, push-buttons, knobs, handles, etc., 
but this is being substituted by asphalts and asphaltites owing to its 
scarcity and correspondingly high price. 

Such mixtures are composed of three classes of materials, viz.: 

(1) Hard native asphalts, asphaltites, or wurtzilite asphalt. 

(2) Vulcanized rubber or resinous substances, including rosin (used alone or 
hardened by heating with lime, oxide of zinc, litharge, etc.), shellac (sometimes added 
in a small proportion), Manila copal, Congo copal. Kauri copal, damar, etc. 

(3) Fillers which may be composed of finely divided mineral matter such as 
calcium carbonate, talc, silica, infusorial earth, clay, slate, carbon black, calcium 
sulphate or terra alba, barium sulphate or blanc fixe, etc.; fibrous mineral matter 
such as asbestos, mineral wool (slag wool), etc.; or fibrous vegetable matter such as 
wood fibres, paper fibres, rag fibres, cotton flock, etc. These may be used either 
singly or in various admixtures. 

Innumerable combinations are used for this purpose, all of which are based upon 
the following general principles: 

As the moulded article is usually subjected to severe usage, it is fundamentally 
important that the ingredients should possess great tensile strength and toughness. 
They should be sufficiently hard to withstand deformation under pressure, and 

1 Annals of the Society for the Advancement of Industrial Science, Berlin, 1891-2, 



BITUMINOUS COMPOSITIONS 



453 



~Brass Bolt and Nut 



fuse sufficiently high not to soften in the sun or any heat to which they may be 
subjected in use. 

The asphalts and asphaltites used should accordingly have a fusing-point not 
lower than 190° F., a penetration at 77° F. (Test 9c) of not exceeding 5, and a tensile 
strength of 77° F. of not less than 10 (Test 11). The function of the resinous matter 
is to enable the bituminous constituents to melt up freely, and impart gloss to the 
finished product. The powdered mineral matter hardens and toughens the mass, 
increasing its tensile strength and m.aking it less susceptible to deformation under 
pressure. The fibrous matter binds the mass together and enables it to stand 
sharp blows without fracturing. 

The constituents are combined by melting together the bituminous and resinous 
bodies, and then stirring in the powdered mineral matter with or without the 
fibres. When the mixture is uniform and while still warm and plastic, it is moulded 
in a suitable die and maintained under pressure while cooling. Most compositions 
of this character are naturally dark in color, due to the bituminous matter present 
and they are often darkened still further by adding a small proportion of black 
pigment, such as lamp-black or carbon-black. In other cases, the mass may be 
colored deep shades of red, brown or green by incorporating an intense pigment of 
the corresponding color. Light colored mixtures, however, are not obtainable. 

Pre-formed Joints and Washers. A bituminous product has recently met with 
considerable success in glazing and sky-light construction,^ consisting of an asphaltic 
cushion enveloped in sheets of asbestos, 
in which the panes of glass are mounted 
and securely bolted together, as shown in 
Fig. 150. 

A represents a steel T-beam, protected 
with galvanizing or other rust-proofing. 
The condensation-gutter is composed of 
sheet steel joined to a waterproof asb.estos 
envelope by an asphaltic composition (p. 
409). The asphaltic cushion and cap-filler 
E are encased in waterproofed asbestos, and 
forced together in between the two sheets 
of glass, forming a pliable, resilient, water- 
tight but firm joint, which prevents the 
glass from being subjected to injurious 
strains. The upper cushion is reinforced 
with a cap of asbestos-protected steel, and fastened ^4th the bolt and nut. 

The cushions B and E are composed of a fluxed asphaltite or a blown petroleum 
asphalt of high fusing-point (in the neighborhood of 250° F.), low susceptibility 
factor (under 20) and absence of brittleness (hardness at 77° F. less than 20 — 
Test 9c), mixed with 10-15 per cent of fibrous asbestos, which binds it together in 
a tough and non-breakable mass. These strips are further protected by being joined 
to an enveloping sheet of asbestos felt, waterproofed with a vegetable drying oil 
or bituminous saturant, similar to that used in manufacturing prepared roofing 
(p. 391). 

Bituminated Cork Mixtures. In Europe, sheets have been prepared for insulat- 




Courtes; 

Fig. 150 



isbestos Protected ^letal Co. 

-Preformed Washers for Sky- 
Hghts. 



lU. S. Pats. 1,227,861 of May 29, 1917 and 1,243,020 of Oct. 16, 1917 to W. P. Waugh. 



454 ASPHALTS AND ALLIED SUBSTANCES 

ing reirigerator plants, ice-chests, cold brine and ammonia pipes, ^ composed of 45 to 
50 parts by weight of finely powdered cork and 100 parts of bituminous binder. 
The composition is prepared in a steam-heated mixing machine similar to that 
described on p. 351. The binder may consist of asphalt, coal-tar pitch or an aque- 
ous emulsion of soft coal-tar pitch with coUodial clay. The mixture is pressed into 
various forms, such as plates, slabs or hemi-cylindrical sections suitable for covering 
pipes. It has a specific gravity between 0.25 and 0.40 and forms a good insulator 
against heat and cold. 

Bituminated cork compositions are also used extensively in the United States 
under the name of " shoe fillers " for filling the insoles of shoes, and composed of a 
mixture of coarsely ground cork, with wax tailings, residual asphalts, or an emulsion 
of asphalt with glutinous substances. ^ 

The mixture is trowelled between the inner and outer soles of shoes while hot 
and plastic, and allowed to set by coohng. It serves to insulate the bottom of the 
foot, and incidentally to replace the more expensive leather. 

Bituminated Leather Mixtures. Shredded leather waste and asphalt have also 
been combined in various ways ^ and proposed for various purposes, as for example 
covering floors, but these have only found a limited use owing to the high price of 
leather. 

Briquette Binders. Coal-tar pitch is most generally used for briquetting coal- 
dust or coke-breeze. The coal or coke powder is mixed with approximately 6-8 per 
cent of coal-tar pitch. Two methods are in vogue, one in which the powder is 
mixed with a moderately soft pitch, added in the melted state, and the other, in 
which it is mixed cold with pulverized hard pitch. In either case, the briquettes 
are formed at high compression under the influence of heat.^ The soft coal-tar 
pitches have a fusing-point between 140 and 170° F. (cube method) and the 
hard pitches between 200 and 225° F. (cube method).^ 

Core Compounds. Coal-tar pitch is used similarly as a binder for the sand cores 
in forming iron and steel castings. A powdered hard pitch, fusing at 225-260° F. 
(cube method) is mixed with the sand and then compressed under the influence 
of heat, to form the cores. 

Miscellaneous Bituminous Products. Bituminous Fuels. The non-asphaltic 
pyrobitumens constitute the principal source of solid fuels for combustion on a 
grate. Liquid bituminous fuels are also used as "fuel oil," including crude petro- 
leums, petroleum residues, by-product tars, and distillates of little commercial value 
produced in refining petroleum and tar. These are atomized under the boiler with 
a steam jet. The tar distillates have also been successfully used in engines of the 
Diesel type in this country and abroad. A detailed description of the technology 
of fuels does not, however, fall within the scope of this treatise. 

lU. S. Pat. 979,310 of Dec. 20, 1910 to W. C. Kammerer; German Pats. 68,532 of 1891; 
122,803 of Sept. 29, 1900; 128,231 of 1902; Kohler & Graefe, Loc. cit., p. 368. 

2 U. S. Pats. 391,265 of Aug. 25, 1891 to S. H. Howland; 808,224 and 808,227 of Dec. 26, 1905 
to W. B. Arnold; 832,002 of Sept. 25, 1906; 855,868 of June 4, 1907; 861,555 of July 30, 1907; 
945,294 of Jan. 4, 1910; 1,032,312 of July 9, 1912; 1,036,931 of Aug. 27, 1912; 1,115,988 of Nov. 
3, 1914; 1,118,161 of Nov. 24, 1914; 1,121,054 of Dec. 15, 1914; 1,121,688 of Dec. 22, 1914, 
1,121,689 of Dec. 22, 1914; 1,134,931 of Apr. 6, 1915; 1,137,679 of Apr. 27, 1915 and 1,227,502 
of May 22, 1917, all to Andrew Thoma; 1,258,272 of Mar. 5, 1918 to H. S. Tirrell 

sQer. Pats. 293,871 of Sept. 1, 1914 and 294,050 of Feb. 13, 1916, both to W. Reiner. 

4 Rudolf Terhaerst, J. Gasbel, 68, 300, 1915. 

6 "Binders for Coal Briquettes," by J. E. Mills, Bull. 24, Bureau of Mines, Wash., D. C, 1911; 
also " Fuel-Briquetting Investigations, July, 1904 to July, 1912," by C. L. Wright, Bull. 58, Bureau 
of Mines, Washington, D. C. 1913. 



BITUMINOUS COMPOSITIONS 455 

Tars and Oils for the Flotation of Ores. During the last few 
years, the flotation process has become an important factor in the 
concentration of certain minerals, including sulphides of copper, lead, 
zinc, silver, iron and other metals, also pure gold, gold telluride, native 
silver and native copper. The best results are obtained with sulphide 
ores. Oxide ores are not amenable to it unless they are first converted 
into the sulphide superficially, by a preliminary treatment with sodium 
sulphide. 

In carrying out the process, the ore is reduced to a fine powder, 
50-mesh material being usually the limit of coarseness. This is then 
beaten into a froth or foam with water and a so-called " flotation oil," 
which causes the heavier ore-mineral to rise to the surface, forming a 
pulp with the froth, and the lighter gangue-mineral to settle out. The 
flotation process has accordingly been aptly termed '' concentration 
upside down." The '* pulp " when it becomes thoroughly charged with 
ore is drawn off, and allowed to subside quietly, whereupon the '' con- 
centrate " will settle out and the " flotation oil " decanted from the 
surface and used over again. The gangue upon being freed from the 
ore, is run to the dump, and the concentrate is smelted in the usual manner. 

The flotation oils may be classified as " frothers " and " collectors," 
the former being largely responsible for the formation of the froth, and 
the latter for holding the particles of ore in suspension. The " frothers" 
or " frothing oils " include commercial pine-oil (obtained from a destruc- 
tive distillation of coniferous woods, p. 190), crude hardwood tar or 
*' pyroligneous acid " or " wood oil " obtained in the destructive dis- 
tillation of maple, birch, beech, etc. (p. 185), turpentine, various ^' essen- 
tial oils " (p. 37), coal-tar creosote, carbolic or '' middle oil," (p. 248), 
etc. The " collectors " or " collecting oils " include crude petroleum, 
liquid residual oil (p. 283), heavy mineral oil distillates (p. 268), 
coke-oven tar (p. 233), water-gas tar (p. 256), etc. The frothing and 
collecting oils are mixed together in proportions depending upon the 
character, composition and nature of the ore to be treated. For a very 
" slimy " ore consisting of fine particles, a larger amount of collecting 
oil will be required, whereas for granular ores a higher proportion of 
frothing oil will be needed. A flotation oil extensively used consists 
of 95 per cent crude coal tar and 5 per cent of pine oil. Another mixture 
which is claimed to give good results contains: pine oil 10 per cent, coal- 
tar creosote 80 per cent, and coal tar 10 per cent. Others have suggested 
the use of: hardwood creosote 40 per cent, coal-tar cresote 50 per cent, 
and coal tar 10 per cent.^ The quantity of flotation oil varies from a 

1 R. E. Gilmore and C. S. Parsons, J. Soc. Chem. Ind.. 37, 97-A, 1918. 



456 ASrHALTS AND ALLIED SUBSTANCES 

fraction of a per cent to 3J per cent by weight of the mineral treated. 
The basic U. S, patent on the flotation process calls for less than 1 per 
cent by weight of oil. The addition of such chemicals as caustic soda, 
and in some cases sulphuric acid or other agents, seems to increase the 
efficiency of the flotation oil and to decrease the time of treatment. 

The frother systems may be classified into the mechanical, pneu- 
matic and vacuum. In the mechanical process air is beaten into the 
mass; in the pneumatic method bubbles of compressed air or other 
gas are blown into the mixture; in the vacuum system the water is 
first charged with gas at atmospheric pressure and bubbles released by 
subjecting the mixture to reduced pressure. Mechanical froths are 
more permanent than those produced by pneumatic means, but the 
former effect a cleaner separation of coarse mineral particles, whereas 
the latter are better adapted for slimes. Increasing the quantity of air- 
bubbles in the pulp, permits using less ^' flotation oil," also a more 
viscous oil, derived for example from gas-works coal tar. 

In general, the following considerations should be carefully observed:^ 

(1) The pulp should be made as thick as possible. 

(2) The proportion of frothing oil to collecting oil should be carefully worked 
out. The more dilute the pulp or the finer the mineral particles the larger the 
proportion of frothing oil will be required. 

(3) The greater the aeration, the smaller the proportion of oil necessary. 

Wood Preservatives. The method of preserving wood for structural 
and other purposes is similar to that already described for impregnating 
wooden paving blocks. Coal-tar creosote is most largely used, but zinc 
chloride is often employed, especially when the wood is to be subjected 
to moderately dry conditions. The method of impregnation is similar 
to that involving the use of creosote. 

In 1915, the total output in the United States from 102 plants included the 
following : 

Cross-ties for railroads 37,085,585 pieces 

Piles 9,308,419 linear ft. 

Poles 125,939 pieces 

Paving blocks 2,936,370 sq.yds. 

Construction timber 142,009,041 board ft. 

Cross-arms 146,219 pieces 

Miscellaneous lumber 13,937,509 board ft. 

Total equivalent to 141,858,963 cu.ft. 

1 " Bibliography of Recent Literature of Flotation of Ores," Bulletin 135, Bureau of Mines, 
Washington, D. C, 1917; "Answers to Questions on the Flotation of Ores," by O. C. Ralston, 
Tech. Paper 149, Bureau of Mines, Washington, D. C, 1917. 



BITUMINOUS COMPOSITIONS 457 

The total preservatives consumed for the foregoing included: 

Creosote 80,859,442 gal. 

Zinc chloride 33,269,604 lbs. 

Miscellaneous 1,693,544 gal. 

The following pounds of creosote are ordinarily used per cubic foot of wood: 

Piles: 

Salt water 16-24 lbs. 

Fresh water 12-16 ' ' 

Ground 8-12 * ' 

Railway ties 5-12 ' ' 

Miscellaneous timber 8-16 ' ' 

When zinc chloride is used, ^-f lb. per cubic foot is injected into the wood. 
There is a difference of opinion regarding the relative efficiencies of creosote and 
zinc chloride, but the former is less expensive, and also enables the wood to be 
used when subjected to moisture. 

Waterproofing Compounds for Portland-cement Mortar and Con- 
crete. The method of incorporating various substances with Portland- 
cement mortar or concrete in the course of their preparation is known 
as the '' integral " system, according to which the waterproofing 
medium is mixed throughout the Portland-cement mortar or mass con- 
crete. This term does not include the application of paints or other 
coatings to the surface of mortar or concrete after it has set. 

Innumerable materials have been exploited for the integral water- 
proofing of Portland-cement mortar and concrete including i^ 

(1) Inert fillers such as finely divided clay, infusorial earth, fuller's 
earth, silica, talc, etc. 

(2) Active mineral fillers such as hydrated lime, aluminium hydrox- 
ide and other inorganic hydroxides, w^hich undergo a chemical change 
during the setting of the cement. 

(3) Water-soluble mineral salts, such as calcium chloride, sodium 
silicate, sodium fluorosilicate. 

(4) Soap compounds including, (a) soluble soaps composed of sodium, 
potassium and ammonium combinations of animal or \^getable oils and 
fats, also resins; (b) insoluble soaps composed of calcium, magnesium, 
aluminium, iron, zinc, lead and other metals combined with animal or 
vegetable fats and oils, or resins. 

(5) Bituminous materials. We are concerned with this last group 
only, as falling within the scope of this treatise. The bituminous mate- 

1 "Tests of Damp-proofing and Waterproofing Compounds and Materials," by R. J. Wig and 
P. H. Bates, Technologic Paper No. 3, Bureau of Standards, Wash., D. C, Aug. 22, 1911; "Electro- 
lytic Corrosion of Iron in Soils," by Burton McCullum and K. H. Logan, Technologic Paper 
No. 25, Bureau of Standards, Wash., D. C, June 12, 1913; "Modern Methods of Waterproofing," 
by M. H. Lewis, Loc. cit.; "Durability of Stucco and Plaster Corstruction," by R. J. Wig and 
J. C. Pearson, Technologic Paper No, 70, Bureau of Standards, Wash., D. C, Jan. 31, 1917. 



458 ASPHALTS AND ALLIED SUBSTANCES 

rials may be divided into two classes, namely, those used in the pure 
state, and those used in an emulsified form. 

Pure Bituminous Materials. Two classes of bituminous substances 
are included in this group, namely, liquid to semi-liquid coal-tar pitch 
(i.e., evaporated coal tar ^) and liquid asphalt. The latter may consist 
of native asphalt,^ residual oil,^ semi-liquid sludge asphalt,^ etc. These 
are mixed with the aggregate after first wetting down the cement and 
sand in preparing Portland-cement mortar; or the cement, sand, gravel 
or broken stone in preparing concrete. Between 10 and 25 per cent 
of soft coal-tar pitch or asphalt are added, based on the weight of the 
dry cement used. As the pure bituminous compounds are naturally 
water-repellent, it requires considerable mixing to distribute them 
uniformly throughout the mortar or concrete, and especially in large- 
sized batches. In this connection, the author wishes to lay particular 
emphasis on the fact that laboratory tests should under no circumstances 
be taken as a criterion of the ease or thoroughness with which bituminous 
substances may be disseminated throughout the mixture. At low temper- 
atures, both soft coal-tar pitch and liquid asphalt become almost solid, 
and under these circumstances it becomes doubly difficult to incorporate 
them. It has also been clearly shown that the introduction of residual 
oil alone materially decreases the tensile and compressive strength of 
mortar and concrete.^ Assuming, however, that with sufficient effort 
the mixture can be made uniform, there is no question that the 
resultant mortar or concrete is improved materially in its water- 
repellent properties.^ 

Bituminous Materials in Emulsified Form. Bituminous emulsions 
tend to overcome the foregoing disadvantages, as they are readily 
miscible with the water used for gauging the sand, cement and crushed 
stone. Instead of depending upon mechanical means for incorporating 
the pure bituminous materials with the aggregate, such as the grinding 
action to which it may be subjected during the process of mixing, 
bituminous emulsions are first brought into suspension by stirring them 

*"Tar and Cement Pavement," by R. Grimshaw, Mvn. Eng., 43, 11, 1912. 

' Eng. Pat. No. 30,091 of Dec. 28, 1910, to J. Krumpelman, who treats an asphaltic shale com- 
posed of liquid asphalt carrying calcium carbonate and clay with hydrochloric acid to separate the 
former, and then dries the resulting powder. 

• Swisa Pat. 44,284 of Dec. 28, 1907, also Austrian Pat. 33,262 of June 10, 1908, both to Dr. 
Gottfried Schruf; U. S. Pat. 1,000,545 of Aug. 15, 1911 to L. W. Page. 

* U. S. Pat. 1,077,689 of Nov. 4, 1913 to Carleton Ellis, who describes the use of sludge asphalt 
neutralized with lime and mixed with fuller's earth or the like. 

'" " Some Experiments with Mortara and Concrete with Asphaltic Oils," by Arthur Taylor and 
Thomas Sanborn, Proc. Am. Soc. Civil Eng., 39, 355, 1913. 

6 'Oil-Mixed Portland Cement Concrete," by L. W. Page, Bull. No. 46, Office of Public Roade, 
Wash., D. C, Aug. 8, 1912; Bull. No. 230. Office of Pubhc Roads, U, S. Dept. of Agr., Wash., 
D. C, July 14, 1915. 



BITUMINOUS COMPOSITIONS 459 

into the gauging water, which then mixes readily with the aggregate, 
requiring httle to no effort, even at low temperatures. 

The efficiency of the bituminous emulsion depends largely upon two 
factors, viz.: (1) the proportion of bituminous matter carried by the 
emulsion, and (2) whether or not its addition will interfere with the 
tensile or compressive strength of the cement mixture when set. 

Three classes of emulsifying agents are in use, including plastic clay, a mixture 
of sodium silicate with barium peroxide, and inorganic hydroxides. These will be 
considered separately. 

{!) Plastic clay is used either for emulsifying coal tar or soft coal-tar pitch,* 
also non-volatile liquid to semi-liquid asphalt, which may either be native or 
derived from petroleum.' Clay is first made into a paste with water, and then 
mixed with the asphalt either in the cold or heated state. Forty parts of dry clay 
will combine with 10 parts of the asphalt, requiring approximately 50 parts of water 
to convert it into an emulsified state. The finished mixture will accordingly carry 
but 10 per cent by weight of the active waterproofing constituent, namely the 
asphalt, the clay merely acting as an inert filler. 

(2) Emulsions prepared from a cut-back coal-tar pitch of soft consistency com- 
bined with sodium carbonate, sodium silicate and barium peroxide.^ These are 
formed in the following manner: 

Coal tar pitch 16 . 15% 

Cut-back with heavy coal-tar oils 48 . 50% 

Mixed with calcined sodium carbonate 1 . 95% 

Water added 4.05% 

Sodium siHcate (30° Baume) 27.50% 

Finally add to the mixture: barium peroxide 1 . 85% 

Total 100.00% 

This mixture contains a large per cent of the active waterproofing constituent, 
but from the author's experience sodium silicate has a decided tendency to delay 
the setting and reduce the strength of Portland-cement mixtures. 

(3) Emulsions prepared by means of inorganic hydroxides capable of forming a 
plastic mixture with water,^ as for example calcium, iron and aluminium hydroxides 
have given very successful results. Residual oils of definite characteristics, soft 
coal-tar pitches or evaporated coal tar may be used, and ground up into a paste 
with a " fat " lime slaked with water. The finished paste is composed of: 

AnhydrouQ calcium oxide 21 . 5% 

BituminouB matter 38 . 5% 

Water 40.0% 

Total 100.0% 

1 Ger. Pat. 68,532 of July 1, 1891 to Griinzweig and Hartmann; F. Raechig, Chem. Rev. Fett- 
Harz-Ind., 17, 169, 1910. 

2 Ger. Pat. 211,877 of Sept. 5, 1906, also Eng. Pat. No. 15,100 of July 16, 1908, both to Julius 
Kathe. 

3 U. S. Pat. 903 287 of Nov. 10, 1908 to H. V. D. Heide; Ger. Pat. 103,733 of May 6, 1899; 
also German application 27,653, 80-b, of Apr. 29, 1907 to Hans Wunner. 

^U. S. Pat. 1,134,573 of Apr. 6, 1915 to Herbert Abraham and H. W. Hainee. 



460 ASPHALTS AND ALLIED SUBSTANCES 

The emulsion contains a large proportion of the active bitumiiaous constituent, 
mixes readily with the gauging water, and may be used in extraordinarily large 
proportions (20-30 per cent of the weight of cement used) without interfering with 
the set and at the same time increasing the tensile and compressive strengths of 
Portland-cement mixtures at least 5-15 per cent, This composition has been 
marketed extensively and gives excellent results in practice. The manufacturers 
recommend 2-12 lbs. of the paste per bag of Portland cement for preparing stucco 
and waterproof-mortar facings, and 1-2 lbs. for Portland-cement concrete. This 
represents the only bituminous waterproofing preparation known to the author 
which can be used under all conditions, insuring a uniform distribution throughout 
the Portland-cement mixture regardless of the temperature or the means used for 
preparing the mixture. At the same time it may be added in sufficient quantities 
to secure absolute waterproof properties without detracting from the strength of 
the structure. 

Methods of Use. The integral method differs from the membrane 
method in that it may be used for waterproofing buildings in the course 
of erection, as well as for repairing the inner surfaces of leaky masonry 
already constructed. The membrane method on the other hand can 
only be used on structures in the course of erection, since it must 
necessarily be applied on the outer surfaces of foundation wallS; to be 
subsequently covered by the earth fill. Similarly, the integral water- 
proofing may be readily repaired should by any chance leakage occur 
later due to settlement or other external causes, whereas it is extremely 
difficult, and in many cases impossible to repair membrane water- 
proofing, owing to its inaccessibility. 

Integral waterproofing compounds are best adapted for use in a 
relatively thin layer or " facing " of Portland -cement mortar, and are 
much more reliable when used in this manner than when incorporated 
throughout the body of Portland-cement concrete, for the reason that 
it is a comparatively simple matter to apply a layer or facing without 
danger of leakage at the joinings, which is not the case with mass con- 
crete construction. 

In applying cement-mortar facings waterproofed with integral compounds, it is 
important to secure a firm bond with the underlying masonry. The old surface 
should accordingly be firm, rough, clean and wet. If the old surface is too smooth, 
it should be roughened by chipping; it may be cleaned by scrubbing with stiff 
brushes, supplemented, if necessary, by washing with muriatic acid; and it should 
be thoroughly wet down with a hose until it has taken up as much M^ater as possible. 
The waterproof facing should be trowelled on with pressure in two or more coats. 
If possible, these coats should be made continuous and applied without interruption 
to avoid joints. If this is not feasible, the day's work should be finished with a 
bevelled edge which should be roughened or chipped to secure a bond or " key " 
where the connection is made on the following day. The first coat should be 



BITUMINOUS COMPOSITIONS 461 

" scratched " before hnrdenirg, and the second coat applied just after the first 
one reaches its final set. The last coat should be trowelled hard and Hoaied. 

Stucco should be ^-| in. thick, trowelled in two coats. \\'aterproof-mortar 
facings used on waterproofing below grade, tanks and swimming pools should be 
applied to the walls in a layer f in. thick, in two coats, and to the floors in a 
layer 1 in. thick in one coat. A 1 : 3 mortar should be used on all exposed work 
and a 1 : 2 mortar on all work protected from the direct action of the weather. 
The facing should be sprinkled with water until it has set hard. Great care should 
be taken to prevent it from drying out prematurely. Interior angles where two 
walls or where the walls and floor meet, should be finished with a rounded surface. 
By proper manipulation, waterproof facings may be applied to old leaky masonry 
surfaces against existing water pressure, which cannot be effectively waterproofed 
by any other means at present known. 

Bituminous emulsions give better results than any other integral waterproofing 
compounds. Saponifiable oils or fats and soaps (both soluble and insoluble) weaken 
the cement mortar or concrete, and are not nearly as permanent on exposure to 
the weather, or capable of continuously resisting the action of moisture. 



CHAPTER XXVII 

BITUMINOUS PAINTS, CEMENTS, VARNISHES, ENAMELS AND 

JAPANS 

This chapter will embrace mixtures of bituminous materials with 
volatile solvents, ranging from pastes to liquids. Bituminous cements 
are manufactured in paste form, whereas bituminous paints, varnishes^ 
enamels and japans are prepared in the liquid state, their respective 
consistencies being regulated by the amount of volatile solvent in- 
corporated. 

BITUMINOUS PAINTS 

Bituminous paints are composed of a bituminous base, a volatile 
solvent, with or without the addition of vegetable drying oils, resins, 
mineral fillers and pigments, and are intended to dry or set by the spon- 
taneous evaporation of the solvent. If any vegetable drying oil is 
present it will contribute little, if at all, to the drying of the paint, 
although it will undoubtedly exert a *' toughening " effect on the coat- 
ing, which will become more pronounced in time. These paints are 
known generally as " solvent paints." The distinguishing character- 
istic between a bituminous paint and a bituminous varnish is that the 
former will set to a firm coat upon the evaporation of the solvent, 
whereas the hardening of the latter is contributed largely by the oxida- 
tion of the vegetable drying oil, which is present in the base in substantial 
proportions. 

Nature of the Base Used. Bituminous paints may be divided into four groups, 
depending upon the composition of the soUd ingredients present in the base, viz.: 

Group 1. Bases containing a bituminous substance, with or without a mineral 
filler. The bituminous substances maj^ include: native asphalts, asphaliites, 
asphaltic petroleums, residual oil, blown petroleum asphalt, residual asphalt, sludge 
asphalt, wurtzilite asphalt, wax tailings, mineral waxes, tars, wood-tar pitch, rosin 
pitch, peat- and lignite-tar pitches, water-gas-tar pitch, oil-gas-tar pitch, coal-tar 
pitch, fatty-acid pitch and bone-tar pitch. 

Group 2. Bases containing in addition to bituminous substances, a resin (rosin, 
rosin esters, damar or sandarac); with or without a mineral filler; with or without a 
colored pigment. 

462 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 463 , 

Group 3. Bases containing in addition to bituminous substances, animal or 
vegetable oils or fats; with or without a mineral filler; with or without a colored 
pigment. The animal or vegetable oils or fats may include: linseed oil, china-wood 
oil, soya-bean oil, fish oil, cotton-seed oil, corn oil, perilla oil, lard oil, mutton fat, 
stearic acid, oleic acid, etc. The oils may be used either in the raw state or com- 
bined with " dryers " (see p. 475), or they may be " bodied " by heating to a high 
temperature, until they thicken by polymerization. 

Group 4. Bases containing in addition to bituminous substances, resins in com- 
bination with animal or vegetable oils or fats; with or without a mineral filler; 
with or without a colored pigment. The "resins" may include: common rosin, 
rosin esters, the damars (including Borneo damar), sandarac, Kauri copal, Congo 
copal, pontianak copal and Manila copal. 

The following ingredients are rarely included, viz.: rubber, wool grease, rosin 
oil, insoluble metal soaps, etc. 

Among the resins: rosin, rosin esters, the damars and sandarac will readily com- 
bine with the bituminous constituents, either by dissolving all of them directly 
in the cold solvent, or by first fluxing them together with heat, and cutting them 
in the solvent afterwards. Fossil resins (copals) will not amalgamate directly with 
the bituminous constituents. They must be melted at a high temperature, and 
first combined with the animal or vegetable oil, whereupon the resulting oleo- 
resinous varnish will flux with the bituminous constituents, either in the cold, or 
upon melting them togethei, A description of the process for manufacturing oleo- 
resinous varnishes does not fall within the scope of this treatise. 

Since the addition of "vegetable or animal oils or fats " improves the weather- 
resistance of bituminous substances, they should accordingly be added wherever 
possible in the role of " flux." The harder the bituminous substance in its raw 
state, and the higher its fusing-point, the larger can be the percentage of the 
animal or vegetable oils or fats incorporated. Rosin, the damars, sandarac or 
rubber, do not add to the weather-resistance of the bituminous materials, as 
these are of themselves deficient in this respect. They will either serve to lighten 
the color of bituminous materials when combined with colored pigments, or in other 
cases to bring about a more perfect union of the constituents, but in either event 
they should be confined to indoor use. On the other hand, fossil resins are highly 
weather-resistant, being equivalent to the asphaltites in this respect. They may 
accordingly be embodied in bituminous paints intended for outdoor use. Paints 
containing fossil resins may be made to carry a large percentage of animal or 
vegetable oils or fats, and will accordingly produce brighter colors with pigments, 
than when oils or fats are used alone. 

The foregoing products may be blended together so the base will be soft, medium 
or hard, with a proportionate range in fusing-point. A base which is naturally soft, 
may be hardened by adding a suitable quantity of mineral filler or pigment. Where 
the base is allowed to remain soft, the paint will be limited in usefulness, and 
adapted only to the painting of -porous surfaces such as masonry or dried-out com- 
position roofings, which will give it an opportunity of soaking into the pores, and 
thus mask the soft properties of the coating. 

Nature of the Fillers and Pigments Used. All sorts of mineral fillers (p. 393) 
have been suggested in connection with bituminous paints, .for use either alone or in 
combination with colored pigments. Their function is to harden the base cr to 
cheapen the paint. The fillers should be powdered very finely (so they will pass a 



464 



ASPHALTS AND ALLIED SUBSTANCES 



200-mesh sieve), otherwise they will tend to settle out. The more finely they are 
powdered and the lower their specific gravity, the longer will they remain in sus- 
pension. 

The colored pigments include the metal oxides (red oxide of iron, yellow ochre, 
chromium oxide, etc.), chrome yellow, chrome green (composed of chrome yellow 
mixed with Prussian blue), graphite, etc. Where the color of the finished paint 
plays an important factor, intense pigments should be employed, as these will be 
required to overcome the dark color of the base. Whites are rarely employed, 
but will produce shades of buff and tan. Should free acids be present in the binder, 
as would be the case if fatty-acid pitch, bone-tar pitch, rosin or rosin pitch were 
used, the range of pigments is narrowed dawn to certain metal oxides. Pigments 
such as chrome green, chrome yellow, zinc oxide, etc., will combine with the free 
acids and form insoluble compounds, causing the paint to sohdify, otherwise 
termed " gelatinizing " or " livering." 

Nature of the Solvents Used. The solvents ordinarily used for manufacturing 
bituminous paints may be divided into four groups, viz.: 

(1) Petroleum products, including gasolene, naphtha (benzine) and kerosene are 
most largely used. Among the naphthas there is a series of products boihng within 
a small temperature range, termed " close-cut distillates," and sold as turpentine 
substitutes. The gasolenes have the lowest flash- and boiling-points and the poorest 
solvent power, whereas the kerosenes have a higher flash- and boiling-point and a 
correspondingly greater solvent action, the naphthas falling in between the two. 
The petroleum solvents and their characteristics are included in the following 
table : 



Solvent. 


Distillation Range. 


Specific 

Gravity at 

15.5° C. 


Flash-point 

° F. (Abei- 

Pensky 

Closed 

Tester). 


Gasolenes. 

Cyrnogene, rhigolene, etc 


Approximately 90% at 70° C. 
Approximately 90% at 85° C. 
Approximately 90% at 100° C. 

Approximately 90% at 125° C. 
Approximately 90% at 150° C 
Approximately 90% at 175° C. 
Approximately 90% at 225° C. 

Approximately 90% at 300° C. 

Approximately 90% at 400° C. 


0.600-0.650 
0.625-0.675 
0.650-0.725 

0.700-0.730 
0.725-0.760 
0.755-0.775 
6.720-0.790 

0.775-0.850 

0.825-0.900 


About —70 


Canadol . . 


About —40 


Petroleum spirits 

Naphthas: 

Light benzine (71-62° B6.) 


About -30 
-15 to +10 


V. M. and P. naphtha (64-55° B6.) 

Turps, substitute (56-51° Be.) 

Turps, substitute (52-48° B6.) 

Kerosenes: 

Illuminating oil (51-35° B6.) 


-5 to +30 
1 80-105 

100-120 


Gas or fuel oils: 

Commercial grades 


150-225 







(2) Coal tar distillates, including benzol, toluol, solvent naphtha and heavy 
naphtha. These evaporate in the orders mentioned, their properties being set forth 
in the following table ^: 

1 Barrett Company, with additions. 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 



465 



Solvent. 



Pure benzol* 

100% benzol 

90% benzol 

50% benzol 

Straw-colored benzol . . 
Pure toluol 

Commercial toluol 

Straw-cofored toluol . . . 
Pure xylol 

Solvent naphtha 

Crude solvent naphtha 

High-flash naphtha. . . . 

Crude heavy solvent \ 

naphtha / 

Heavy naphtha 



Color. 



Water white 
Water white 

Water white 
Water white 



Straw 
Water white 

Water white 

Straw 
Water white 

Water white 

Dark straw 
Water white 

Amber to red 

Deep amber 
to dark red 



Distillation Range. 



100% within 2° C. 
Approximately and at least \ 

100%o at 100° C. / 

Approximately and at least \ 

90% at 100° C. / 

Approximately and at least 1 

50% at 100° C. I 

Approximately and at least | 

90% at 120° C. J 

At least 80% at 100° C. 
100%, within 2° C. 
Not over 5% at 100° C. ] 
Approximately and at least [ 

90% at 120° C. J 

At least 80% at 120° C. 
100% between 135° and 145° C. 
Not over 5% at 130° C. ] 

Approximately and at least [ 

90%o at 160° C. J 

At least 80% at 160° C. 
100% between 150° and 200° C. 
Not over 10%, at 160° C. \ 
At least 90% at 200° C. / 
Not over 10% at 160° C. \ 
About 70% at 200° C. / 



Spccfic 

Gravity at 

15.5° C. 



875 to .885 
875 to .885 

870 to .882 
868 to .880 



Flash-point °F. 
(Abol-Pensky 
Closed Tester). 



-10 



-f23 



862 to .882 


About 30 


864 to .874 


+7 


864 to .874 


About 15 


862 to .872 


About 17 


860 to .870 


About 85 


862 to .872 


About 78 


862 to .882 


About 78 


870 to .880 


Not below 100 


940 to .986 


Not below 90 


925 to .950 


About 109 



• Pure benzol should crystallize at approximately 5° C. 

(3) Solvents derived from wood, including pure spirits of turpentine, wood tur- 
pentine, rosin spirits, light wood oil, wood creosote oil, pine oil, acetone oil, etc. 
(see p. 190). Their properties are shown in the following table: 



Solvent. 


Distillation Range Deg. C. 


Specific 

Gravity at 

15.5° C. 


Flash-point 

° F. (Abel- 

Pensky 

Closed 

Tester). 


From hardwoods: 

Light acetone oil 


75-160 

100-215 

90% below 1«50 

90% below 400 

95% below 170 \ 
eO% below 170 / 
90% below 190 

190-240 
80-200 

225-400 


0.825-0.830 
0.883-0.887 
0.860-0.900 
0.930-0.980 

0.860-0.870 

0.850-0.870 
0.925-0.950 
0.900-0.940 
0.940-0.990 


Below 20 


Heavy acetone oil. . . 


Below 50 


Light wood oil 


Below 50 


Heavy wood (creosote) oil 


Above 160 


From soft (resinous) woods: 




Steam-distilled wood turpentine 

Destructively distilled wood turpentine 
Pine oil 


105-108 

Below 25 
130-170 


Rosin spirits 


Below 50 


Rosin oil. . 


220-280 







466 



ASPHALTS AND ALLIED SUBSTANCES 



(4) Manufactured chemicals, including carbon disulphide, carbon tetrachloride, 
di-chlor methane, etc. These evaporate very readily, the carbon disulphide being 
highly inflammable and the vapors explosive. Carbon tetrachloride and di-chlor 
methane similarly evaporate rapidly, but form non-explosive and non-inflammable 
solvents,^ and may be used to raise the flash-point of other solvents susceptible to 
ready ignition alone. ^ 

The properties of the chemical solvents adapted for use with bituminous sub- 
stances are included in the following table: 



Solvent. 


Distillation Range Deg. C. 


Specific 

Gravity at 

15.5° C. 


Flash-point 

° F. (Abel- 

Pensky 

Closed 

Tester). 


Carbon disulphide 

Acetone — C. P 


46-47 

56-57 

56-90 

About 140 

180-183 

208-215 

40-41 

60-62 

75-77 


1.265-1.272 
0.790-0.800 
0.845-0.850 

0.876 

1.027 

1.187 

1.377 
1 . 485-1 . 500 
1 . 580-1 . 600 


-48 
i+14 


Acetone — commercial 


Amyl acetate 


72 


Aniline . . . . 


170 


Nitrobenzol. . . 


194 


Di-chlor methane (methylene chloride) 
Chloroform 


None 

None 


Carbon tetrachloride 


None 







Note. — Grain alcohol, wood alcohol, etc., cannot be us.ed for bituminous mate- 
rials, as they are deficient in solvent properties. Other solvents, including ether, 
chloroform, etc., possess good properties, but are not generally used on account 
of their high price. 

The following table ^ shows the comparative evaporation times of certain com- 
mercial solvents, tested by allowing 2 cms. of each material to evaporate under 
similar conditions from a metal surface 3| in. square: 



Carbon disulphide 3^ min. 

Carbon tetrachloride 4| 

Pure benzol 10 

100% benzol 13| 

90% benzol ^ 14 

Straw-colored benzol 18 

50% benzol 23 

Pure toluol 29 

Commercial toluol 33 

Straw-colored toluol 36 

Xylol 89 

Solvent naphtha 107 



Crude solvent naphtha. ^. . 121 min. 

High-flash naphtha 205 ' ' 

Crude heavy solvent naphtha 290 " 

Heavy naphtha 303 " 

Turpentine 142 ' * 

Wood turpentine 480 " 



80° gasolene , 

70° gasolene 

66° benzine 

62° benzine 

Petroleum turps substitute (42°)., 
Kerosene 



4 

8 

16 

18 

346 

475 



The proportion of solvent used, depends upon three factors: (1) the nature of 
the bituminous base, (2) the " capacity " of the solvent, and (3) the consistency of the 
paint desired. 

In general, the higher the susceptibflity of the base, the lower will be the viscosity 
of the resulting paint. Upon running parallel tests, with the same percentage by 



lU. S. Pat. 835,113 of Nov. 6, 1906, to S. G. Penney. 

^2" Flash, Fire and Explosion Tests on Mixtures of Carbon Tetrachloride and Naphtha,' 
E. A. Barrier, Jour. Ind. Eng. Chem.-, 2, 16, 1910. 
' Barrett Co. with additions. 



by 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 467, 

weight in all cases of the respective solvents, it will be found that residual asphalt, 
sludge asphalt, wood-tar pitch, water-gas-tar pitch, oil-gas-tar pitch and the coal- 
tar pitches will form paints of lower viscosity than paints prepared from fluxed 
asphaltites, blown petroleum asphalt, wurtzilite asphalt and the non-susceptible 
fatty-acid pitches. With bituminous materials having a high susceptibility factor, 
the fusing-point of the base exerts comparatively little influence on the viscosity 
of the completed paint. Bases that are hard, and at the same time possess " tough 
and rubber-like " properties (i.e. a low susceptibility factor, considerable elasticity, 
resilience and tenacity) when used alone, are apt to gelatinize after they have been 
dissolved in the volatile solvent. In other words, although the paint when first 
made up may appear liquid, it will after a time become transformed into a jelly- 
like mass. This is particularly apt to occur with hard and " rubbery " fatty-acid 
pitches, wurtzilite asphalt and gilsonite. The specific gravity of the base has also 
a bearing on the paint's consistency. Since it is customary to measure the base 
and solvent by weight, it follows that the higher the specific gravity of the base, 
the smaller will be its volume for a given weight. Hence a base of high gravity 
will form a paint of lower viscosity than an equal weight of a low gravity base, but 
substantially the same in other respects. 

The " capacity " of the solvent also has an important bearing upon the viscosity 
of the paint. The greater the solvent action of the menstruum, the smaller per- 
centage by weight will be required to produce a paint of a given viscosity. In 
general, aromatic hydrocarbons are superior in solvent action to aliphatic hydro- 
carbons. Coal-tar products and those derived from wood distillation constitute 
better solvents than petroleum products. Similarly, distillates from aromatic petro- 
leum are relatively better solvents than those produced from strictly aliphatic 
petroleum. In all cases the higher the molecular weight of the hydrocarbons, the 
better will be the solvent action. Derivatives such as carbon disulphide, carbon 
tetrachloride, chloroform, di-chlor methane, ether, etc., are generally better solvents 
than the corresponding pure hydrocarbons from which they originated. For the 
reason previously explained, the specific gravity of the solvent has a bearing on the 
consistency of the paint, from the standpoint of percentage expressed by weight. 

The weight of solvent in commercial bituminous paints ranges from 20 to 80 
per cent. The smaller percentages are used in heavy-bodied paints intended for 
coating masonry, for sealing the joints of composition roofing, and for appHcation 
to porous surfaces. Light-bodied paints containing the larger percentages of solvent 
are used where it is desired to secure great penetration, rapid drying properties, 
or where the paint is used for " dipping " purposes. 

Mineral waxes alone are difficultly soluble in most solvents (see p. 310). Asphalt- 
ites and asphalts dissolve in the following solvents, approximately in the order 
mentioned, viz.: carbon disulphide, carbon tetrachloride, distillates from coal tar, 
resinous woods and petroleums. Comparing products of the same fusing-point, 
we find that blown petroleum asphalts are most soluble, then come native asphalts, 
sludge asphalt, wurtzilite asphalt, and lastly the residual asphalts. 

Tar pitches produced from the destructive distillation of bones, wood, peat, 
lignite and coal are more difficultly soluble than asphaltic materials and pitches 
not derived from tars (e.g., rosin pitch and fatty-acid pitch). Tar pitches dissolve 
most readily in the following solvents, approximately in the order mentioned, viz., 
carbon disulphide, coal-tar distillates and distillates from resinous woods. Of the 
pitches: rosin pitch, fatty-acid pitch, bone-tar pitch, peat- and lignite-tar pitches 



468 



ASPHALTS AND ALLIED SUBSTANCES 



are relatively the most soluble, and oil-gas-tar pitch, water-gas-tar pitch, wood-tar 
pitch and coal-tar pitch are least soluble, ranging approximately in the sequence 
stated. The solubihty of bituminous substances may be increased by fluxing with 
such materials as rosin, animal and vegetable oils or fats, wax taihngs, fatty-acid 
pitch, and in some cases residual oil derived from aromatic petroleums. 

Methods of Manufacture. When all the ingredients of the base fuse 
at comparatively low temperatures, the simplest method consists in 
stirring them with the solvent in a closed steam- jacketed tank pro- 
vided with an agitator. The temperature should be raised close to the 
boiling-point of the solvent, and the stirring continued until the 
solution is complete. When some of the materials melt at high tem- 
peratures it is advisable to flux them with the remaining ingredients 
of the base by direct fire, either in a small tank mounted on wheels, 
known as a ''varnish kettle," heated by coke burning in a pit, on 
grate bars sunken 8 to 12 in. below the floor level (Fig. 151), or in a 




Fig. 151.— Varnish Kettle. 



large stationary hemi-cyhndrical melting tank (p. 69). When the 
melting is effected in a varnish kettle, after the ingredients have been 
fluxed together, it is withdrawn a safe distance from the fire, cooled to 
slightly under the boiling-point of the solvent, which is then gradually 
introduced, small quantities at a time, stirring continuously with a 
paddle. When the base has been melted in a stationary hemi-cylin "ri- 
cal kettle, it is run by gravity or pumped into a closed cylindrical tank 
equipped with a stirring device, and after cooling sufficiently, the solvent 
is run in slowly, with continuous stirring until the solution is complete. 
The second method is used for preparing large quantities of paint 
in one charge. 

Sometimes the bituminous paint is mixed cold in various propor- 
tions with oleo-resinous varnishes manufactured in the usual manner, 
either to increase its weather-resistance or for purpose of lightening 
its color, when colored pigments are to be incorporated. Pigments and 
fillers may be mixed with the paint by simply stirring them together 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 



469 




Courtesy of Kent Machine Works. 
Fig. 152. — Paint-grinding Mill. 



in a tank provided with an agitator, or by grinding the mineral in- 
gredients and sufficient paint to form a paste in an enclosed buhr-stone 
mill, as illustrated in Fig. 152, and then thinning the paste to brushing 
consistency with an additional quantity of bituminous paint, or in 
certain cases with a volatile solvent. 
Fillers or pigments ground in accord- 
ance with the latter procedure are 
less apt to settle on standing, than if 
simply stirred into the paint. It 
should be noted, however, that even 
under the best conditions, fillers and 
pigments are more apt to settle from 
bituminous solvent paints than from 
oil paints. This is probably due to 
the better buoying and lubricating 
properties of the oil on the mineral 
particles. 

Types of Bituminous Paints. Ma- 
sonry Paints. These are used for 
painting brick, stone, or concrete 
surfaces, usually above ground, to 

prevent the inroads of dampness or moisture. Masonry paints often 
termed *' damp-proofing paints," are divided into two classes, viz., 
clear and black. 

Clear damp-proofing paints are used for painting the outside of 
exposed walls, and are generally made up from a base composed largely 
of paraffine wax in combination with resinous, oily or fatty constituents. 
Paraffine wax alone is only slightly soluble in most solvents, and has 
the disadvantage of crystallizing out at low temperatures. The addi- 
tion of resins, vegetable or animal oils and fats will prevent this to a 
certain extent, and also maintain the necessary light color. These 
paints are intended to penetrate the pores of the masonry, and are 
therefore made thin in body, containing a large proportion of solvent 
(60 to 80 per cent by weight). The base is usually prepared of a low 
fusing-point to augment its solubility; and petroleum distillates, with 
or without the addition of wood distillates are generally used as solvents. 
Clear damp-proofing paints spread from 250 to 500 sq.ft. per gallon, 
depending upon the porosity of the underlying surface. 

Black damp-proofing paints are made from asphaltic mixtures, 
water-gas-tar pitch, oil-gas-tar pitch and the various coal-tar pitches, 
used either alone or in combination with animal or vegetable fats or 



470 ASPHALTS AND ALLIED SUBSTANCES 

oils. The base is prepared of a fairly low fusing-point (140 to 160° F. 
by the K. and S. method) and " cut " to a heavy body. Asphaltic bases 
are dissolved in 40 to 60 per cent of petroleum distillate, figured on the 
total weight; and bases derived from tars dissolved in 30 to 45 per 
cent of coal-tar distillate. This class of paints is used for coating the 
inside of exposed masonry walls, and may be plastered upon directly, 
thus dispensing with the furring and lathing. The best practice con- 
sists in applying two coats of the damp-proofing paint to the inside of 
the wall, allowing each to dry about twenty-four hours. The plaster 
may then be trowelled directly on the paint, with which it forms a 
good bond. Black damp-proofing paints containing saponifiable mate- 
rials such as vegetable or animal oils and fats, or resins, bond better with 
the plaster than those made exclusively of asphaltic or coal-tar mix- 
tures, in which latter case the bond tends to weaken when the paint 
ages. The paint should spread between 50 and 60 sq.ft. per gallon 
for the first coat, or 70 and 80 sq.ft. for the second, depending upon 
the character of the surface to which it is applied. 

Paints for Recoating Prepared Roofings. These fall into two groups, 
namely those intended to repaint prepared roofings composed of as- 
phaltic and coal-tar products respectively. For the former, asphaltic 
paints are used, and for the latter, paints prepared from pitches, and 
generally coal-tar pitch. For the cheapest paints, straight-distilled coal 
tar or crude asphalt-bearing petroleum are used. These form coatings 
of a nondescript character, due to their variable composition, and they 
also evaporate and harden slowly. 

Higher grade paints of this class are prepared from substantially 
the same compositions used for the coatings of prepared roofings (p. 392), 
but of a slightly softer consistency and lower fusing-point (140 to 160, 
K. and S. method). These are dissolved in approximately an equal 
weight of solvent. When used as lap-cement, a smaller proportion of 
solvent is incorporated, and the paint is accordingly made heavier in 
body. Asphaltic paints should not be used on roofs containing coal-tar 
products, or vice versa. 

In all cases, it is important that the base should be plastic, and have the same 
physical characteristics as the bituminous roofing to which it is applied. Paints 
containing a preponderance of " vegetable drying oils " such as linseed, china- 
wood, etc., fail to answer satisfactorily on bituminized roofings, for the following 
reasons: 

(1) Vegetable drying oils oxidize to an elastic substance known as " linoxyn," 
entirely devoid of plasticity, with the result that such coatings soon crack, check 
("alligator "), and in certain cases peel off the roofing, when exposed to the weather. 

(2) Because the dark-colored bituminous constituents have the property of dif- 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 



471 



fusing or drawing through a coating of dried or oxidized vegetable oil, upon being 
subjected to the sun's heat, thereby causing the paint to assume a badly discolored 
or mottled appearance. 

Bituminous materials interfere with the oxidation of vegetable drying oils, and if 
an excess of the former is present in the base, the entire composition will assume a 
" plastic " consistency, and the drying of the oil will be retarded. On the other 
hand, if the vegetable drying oil is in excess, it will oxidize in spite of the bitumi- 
nous matters. The following table shows the relation between the consistometer 
hardness at 77° F. (Test 9c), and the percentage of commercial boiled hnseed oil 
in admixture with gilsonite. 



Gilsonite, 
Per Cent. 


Boiled Lirseed 
Oil, Per Cent. 


Consistency at 

11^ F. 

(Test 9c). 


Remarks. 


100 
95 
90 

85 



5 
10 
15 
20 
25 
50 
75 
85 
100 


100.0 

98.0 

85.5 

70.0 

50.0 

20.5 

3.1 

0.0 

0.0 

0.0 


Unsuitable for coating prepared roofings. 


80 
75 
50 


\ Most desirable range • Probable range permissible. 


25 

15 




Unsuitable for coating prepared roofings. 



Many unsuccessful attempts have been made to adapt linseed-oil-pigment-paints 
for coating prepared roofings, as for example, by first applying a priming coat of 
sodium silicate and rosin, ^ surfacing the roofing with fine sand,^ etc. 

To successfully paint prepared roofings in colors, a weather-proof plastic bitumi- 
nous binder must be selected, having a light brown color in a thin layer (1-2 mils 
thick) when viewed by transmitted light on glass; otherwise yielding a brown streak 
on porcelain (Test 6). Gilsonite and certain forms of fatty-acid pitch (Group 1); 
mixtures of these with certain resins (Group 2); mixtures of these with a small 
proportion of vegetable oils or fats (Group 3); or mixtures containing both resins 
and vegetable drying oils (Group 4), will answer satisfactorily for this purpose, 
since they may be mixed with pigments without obliterating their color, as would 
be the case if dark-colored bituminous mixtures yielding a black streak were used.' 
The base is dissolved in the volatile solvent and finally the colored pigment or 
mixture of pigments ground in The ratio of pigment will vary from half to the 
same weight as the base, depending upon the intensity of the pigment, the opacity 
of the base, and the color of the paint desired. The percentage of volatile solvent 
must be increased slightly when pigments are used, due to the fact that these con- 
tribute to the body of the paint. A typical mixture will contain 30 per cent base, 
20 per cent pigment, and 50 per cent volatile solvent. 



»Ger. Pat. 219,181, of 1907 to H. Engelhardt. 

2 U. S. Pats. 291,600 of Jan. 8, 1884 to Josiah Jowitt; 385,057 of June 26, 1888 to Alexander 
Jones; 791,312 of May 30, 1905 to C. S. Bird. 

3 U. S. Pat. 824,898 of July 3, 1906 to Herbert Abraham. 



472 ASPHALTS AND ALLIED SUBSTANCES 

Bituminous Paints for Metal or Wood. All sorts of bituminous 
paint mixtures have been recommended for painting metal and wooden 
surfaces.^ 

Bituminous paints give better results out-of-doors on metal than on wooden 
surfaces, although most manufacturers recommend them indiscriminately for both 
types of construction. However, it should be noted that any resinous constituents 
in the wood will act deleteriously on the paint after a time, due to their solvent 
action on the bituminous constituents present. Bituminous varnishes and enamels 
may safely be recommended under these conditions, since the excess of drying oil 
on oxidation becomes immune to the resinous constituents. If manufactured 
according to correct principles, bituminous paints will give fair service on exposed 
metal work, including metal roofs, corrugated iron, farm implements, etc., and 
although inferior in weather-resistance to bituminous varnishes and enamels, they 
are at the same time considerably less expensive. Bituminous paints have been 
used successfully for resisting the corrosive action of acids, alkaline solutions, 
cyanide liquors, etc. They are, in fact, more resistant to these chemicals than any 
other types of paints at present known. When used to withstand acids they will 
afford better protection to wood than to metal, due to the fact that wooden sur- 
faces are in themselves more resistant to the action of acids, and being porous will 
absorb a greater quantity of paint, thus insuring a greater " factor of safety." 

Bituminous paints will not give satisfaction when exposed to vapors or the direct 
contact of solvents for bituminous materials, such as petroleum products, illuminat- 
ing gas, the so-called " gas-drip " condensing out of gas mains, turpentine, exuda- 
tions of resinous woods, or the like. They may be applied on top of dried coatings 
of linseed oil paint or varnish, but should not be recoated therewith, as bituminous 
materials will form an unstable foundation, and for the reasons previously cited 
will act injuriously on the superimposed coating of dried linseed oil (linoxyn). 

Certain bituminous paints, prepared without the use of mineral fillers or pig- 
ments are used for electrical insulating purposes where a rapid " air-drying " paint 

1 U. S. Pats. 109,757 of Nov. 29, 1870 to T. C. Rice, composed of coal tar, Venetian red and 
solvent; 188,646 of Mar. 20, 1877 to A. K. Lee, composed of asphalt alone and solvent; 207,096 
of Aug. 20, 1878 to M. B. Bailey and 243,990 of July 5, 1881 to J. S. Smith composed of fatty- 
acid pitch and solvent; 235,365 of Dec. 14, 1880 to A. K. Lee, composed of asphalt, linseed oil, 
pigments and solvent; 237,017 of Jan. 25, 1881 to J. F. Hoffman, composed of asphalt, rosin 
and creosote oil; 240 899 of May 3, 1881 to J. L. Fauss, composed of coal-tar pitch, red iron 
oxide, ground slate and solvent; 243,990 of July 5, 1881 to J. C. Smith composed of fatty-acid pitch 
and solveat; 338,868 of Mar. 30, 1886, 348,993, 348,994 and 348,995 of Sept. 14, 1886, all to 
T. J. Pearce and M. W. Beardsley, composed of residual asphalt dissolved in carbon disulphide; 
369,301 of Aug. 30, 1887 to G. W. Swan, composed of residual asphalt and pigments dissolved in 
benzine: 391,927 of Oct. 30, 1888 to J. A. Titzel composed of gilsonite, a small proportion of 
rubber, linseed oil, colored pigment and solvent; 394,396 of Dec. 11, 1888 to F. M. Reed, com- 
posed of asphalt, rosin, lime, stearine, red iron oxide and solvent; 701,743 of June 3, 1902 to 
T. L. Lee, composed of coal-tar pitch, dead oil, benzol and yellow ochre; 768,101 of Aug. 23, 1904 
to F. M. Whitall, composed of wurtzilite asphalt and solvent; 835,113 of Nov. 6, 1906 to S. G. 
Penney, composed of blown petroleum asphalt, carbon tetrachloride and petroleum naphtha; 
853,354 of May 14, 1907 to August Gross and A. C. Horn, composed of asphalt, Portland cement 
and pine oil; 967,337 of Aug. 16, 1910 to D. T. Day, containing nitrated asphaltites dissolved in a 
solvent; 984,477 of Feb. 14, 1911 to M. D. GrifBn, ct al., containing gilsonite, wurtziHte-asphalt, 
boiled linseed oil and solvent; Eng. Pats. No. 1932 of Jiine 13, 1868, to Charles Humfrey, con- 
taining fatty- acid pitch, coal-tar pitch or residual asphalt dissolved in a volatile solvent; No. 12j632, 
Nov. 1, 1887, to J. H. Lyman, describing the use of residual asphalt dissolved in benzine.,; . 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 473 

is required. They are usually marketed under the erroneous term " air drying 
varnish," but are in reahty air-drying paints. The author has examined specimens 
capable of withstanding 1000 volts per mil in thickness. 

For manufacturing inexpensive machinery and farm implements, bituminous 
paints may be used for dipping purposes, upon thinning with additional solvent. 

BITUMINOUS CEMENTS 

These are of plastic, trowelling consistency and adapted for repair- 
ing metal or composition roofing, damp-proofing the inside of masonry- 
walls above ground, and to a limited extent for waterproofing the out- 
side of foundation walls below ground. The cement may be composed 
of two or more of the following constituents, viz.: 

(1) A base containing one or more bituminous materials with or 
without the addition of vegetable oils, resins, etc. The ingredients 
should preferably be blended together in such proportions that the 
mixture will show a fusing-point (K. and S. method, Test 15a) between 
135 and 175° F., a consistometer hardness (Test 96) of 5 to 25 at 77° F., 
a susceptibility factor (Test 9d) below 25, and substantially complete 
solubility in the solvent used. 

(2) Mineral fillers are sometimes added, comprising any of the prod- 
ucts, such as clay,^ etc., used for filling the coatings of prepared roofings 
(p. 393). Occasionally colored mineral pigments are used to impart 
to the cement, a color other than the inherently dark color of the 
bituminous materials. Even when employed in moderately large pro- 
portions, and of a strong intensity, they will result in comparatively 
dark hues. 

(3) Fibrous matter is often added to bind the base together, and 
form a tougher mass when set. The fibres may either be of mineral, 
vegetable or animal origin, including asbestos,^ slag wool, cotton flock, 
shoddy, rag fibres, etc. These are added in percentages not to exceed 
15 per cent of the total. The waste product obtained in the manufacture 
of bituminized roofing or shingles may also be used for this purpose.^ 

(4) A volatile solvent in which the base will dissolve, consisting of 
petroleum products (e.g., gasolene, naphtha, or kerosene), distillates from 
rosin or wood (e.g., turpentine, wood turpentine, pine oil, wood creosote 
oil, etc.), tar distillates (e.g., benzol, coal-tar naphtha, solvent naphtha, 
creosote oil, etc.), used singly or in various combinations. The per- 
centage of solvent will range from 10 to 25 per cent in weight, depend- 

iTJ. S. Pat. 145,705 of Dec. 16, 1873 to Horace Wheeler. 

2 U. S. Pats. 76,773 of Apr. 14, 1868; 76,773 Pe. 5948A and 5949B of June 30, 1874, all to 
H. W. Johns. 

3 U. S. Pat. 1,253,454 of Jan. 15, 1918 to Herbert Abraham. 



474 ASPHALTS AND ALLIED SUBSTANCES 

ing upon the nature of the base and the desired consistency of the 
cement. 

The cement is manufactured by combining the base with the volatile 
solvent in one of two ways: 

(1) By melting together the constituents in a so-called *' varnish 
kettle " (p. 468) over direct fire heat, cooling until the mass commences 
to thicken and then gradually stirring in the solvent, small quantities 
at a time. 

(2) By " cutting " the ingredients of the base with the solvent, in 
a closed steam-heated tank provided with a mechanical stirrer. The 
components of the base are weighed out separately, then the solvent 
added, the cover or cap of the tank screwed in place and steam turned 
on. The stirring is continued until the solution is complete, whereupon 
the charge is allowed to cool, the cover removed and the contents with- 
drawn. When mineral fillers, pigments or fibrous matters are to be 
used, they are incorporated cold, either by hand or with a power mixer. 

The cement is ordinarily applied with a trowel in a layer from 
Ye to i in. thick, covering 25 to 12| sq.ft. respectively per gallon on a 
fairly smooth surface. The volatile solvent should evaporate within 
twenty-four hours, leaving the base and any mineral filler or fibrous 
constituents in the form of a weather-proof coating capable of withstand- 
ing the highest sun temperatures without softening or running, and suffi- 
ciently tough to withstand walking, attrition of the elements, or any 
expansive or contractive strains to which it may be subjected. 

BITUMINOUS VARNISHES 

These correspond to Groups 3 and 4 in the preceding classification 
(p. 463), but carry a larger percentage of vegetable drying oil, with the 
fillers and pigments absent. In other words, they consist of a bituminous 
base, a volatile solvent, animal or vegetable " drying oils " with or without 
the presence of resins. The proportion of oils should be sufficient so the 
base will possess a Hquid to semi-liquid consistency and harden at room 
temoerature by oxidation of the oils. Hard bituminous substances only 
are suitable for manufacturing varnishes, including the hard native 
asphalts, asphaltites, hard residual asphalts, wurtzilite asphalt, hard 
rosin pitch, hard wood-tar pitch, hard fatty-acid pitch and hard bone-tar 
pitch. Those ordinarily employed include asphaltites, hard native 
asphalts, hard fatty-acid pitches, and less frequently wurtzilite asphalt. 
The oils generally employed include linseed and china-wood, or a mixture 
of the two. 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 475 

Asphaltic varnishes are prepared in the same manner as oleo- 
resinous varnishes, namely, in a varnish kettle. When fossil resins 
(copals) are to be used, they are first melted up or " depolymerized " 
at a temperature of 500 to 550° F., and when rendered fusible, the oils 
are added in the customary manner, then the dryers, and finally the 
asphalt or asphaltite. When the mixture has been thoroughl}^ melted, it is 
allowed to cool and thinned with one or more volatile solvents. 

When the varnish consists solely of bituminous matter and drying 
oil, one of three procedures may be followed, viz.: 

(1) The oil or mixture of oils in the raw state may be fiuxed with 
the bituminous matter, thereupon '' bodied " at 500 to 525° F. until 
the mass becomes stringy, cooled to 400 to 450° F., then the dryers 
incorporated, and finally thinned with a volatile solvent. 

(2) The oil or mixture of oils may first be bodied alone, then fluxed 
with the bituminous matter, the heat raised to about 500° F., cooled 
to 400 to 450° F., the dryers incorporated, and finally thinned. 

(3) The oil, or mixtures of oils may first be bodied as in the fore- 
going, cooled to 400 to 450° F., the dryers incorporated, fluxed with the 
bituminous matter, cooled and thinned. 

Each varnish maker has his own views as to the relative efl&ciency 
of these procedures. 

Varnishes made from linseed oil alone are more durable on exposure to the 
weather, but they dry slower than mixtures containing china-wood oil. When 
china- wood oil is used, it must be heated above 500° F., to prevent the varnish 
drying with a " flat " or " frosted " appearance, but it should never be heated 
alone above 500° F., otherwise it will gelatinize and become infusible. The presence 
of 30 per cent linseed oil, resins or bituminous matter, or a combination of these 
will retard gelatinization but not prevent it. China-wood oil mixtures containing 
50 per cent of one or more of these substances may be heated without danger 
of gelatinization. 

Bituminous varnishes ordinarily contain 15 to 20 gallons of oil per 100 lbs. 
of bituminous matter, or mixtures of b:tuminous matter and resin. The durability 
of the varnish on exposure is in proportion to the quantity of oil present, so-called 
" long-oil varnishes " being more durable than " short-oil varnishes." Rosin esters 
have recently been used in combination with asphalts in this class of varnishes 
with good results, and prove fairly durable on exposure and waterproof. 

The following dryers are generally used: 

(1) Lead dryers in amounts ranging from 2-4 per cent by weight of the oil. 
Since the asphaltic varnishes are dark in color, it is imnecessary to use " pale '' 
dryers, and consequently Utharge (PbO) or red lead (Pb304) will answer satis- 
factorily. 

(2) Manganese dryers in percentages of 1-2 per cent, usually in the form of 
manganese dioxide (MnOa). 

(3) Cobalt dryers in percentages of i-5 per cent of the oil, and added in the form 
of cobalt acetate (CoAj). 



476 ASPHALTS AND ALLIED SUBSTANCES 

The best results are obtained by using combinations of lead and manganese; 
manganese and cobalt; or lead, manganese and cobalt in approximately the ratios 
specified. The addition of prepared liquid dryers to the cold varnish will not 
answer in the case of asphaltic varnishes as with oleo-resinous varnishes. 

The following represent typical specifications for this type of varnish: 

Specifications (M-L-N-55) issued by the U. S. War Dept., July, 1908, provide 
that "Asphalt varnish must be made of pure high-grade asphalt of the very best 
quality, of pure linseed oil and pure turpentine dryers only, and must not contain 
less than 20 gal. of prepared linseed oil to 100 gal. of varnish. It must not 
flash below 103 '^ F. (open tester). It must mix freely with raw linseed oil in all 
proportions; it must be clear and free from sediment, resins and naphtha. When 
flowed on glass and allowed to drain in a vertical position, the film must be per- 
fectly smooth, of good body, and must equal in this last respect the standard 
sample. It must set to touch in from 1^-2| hours, and must dry hard in less than 
20 hours at 70° F. When dry and hard it must not rub up and powder under 
friction of the finger. The application of heat must quicken the time of drying 
and give a harder film." 

Specifications (52V-la) issued by the U. S. Navy Dept., July 20, 1913, provide 
that "Black asphalt varnish must be made exclusively from pure high-grade asphalt 
of the very best quality, pure linseed oil, petroleum spirits, and lead-manganese 
dryers. It shall contain petroleum spirits, not less than 50 per cent nor more than 
55 per cent by volume. The asphalt and linseed oil must be present in such pro- 
portions as to yield a film, after thorough drying, which shows no tendency to rub 
up or powder under friction of the finger. The flash-point by the open tester must 
not be below 100° F. It must mix freely with raw linseed oil. When flowed on 
glass and allowed to drain it should dry hard within 20 hours at 70° F., the film 
to be smooth and to possess full hiding power." 

Varnishes containing china-wood oil will harden more rapidly than the fore- 
going. Bituminous varnishes will withstand exposure to the weather even better 
than oleo-resinous varnishes, although their use is limited by their inherently dark 
color, which restricts them for coating metal work either out-of-doors or in-doors. 
They produce lustrous coatings on drying. Other things being equal the blacker 
the streak on porcelain of the bituminous base, the more intense will be the color, 
covering power and opacity of the resulting varnish. If too large a proportion 
of the resin or oil is used in its manufacture, the varnish will dry with a trans- 
lucent film possessing a brownish black to deep brown color, having little value 
for coating structural objects. Such varnishes are sometimes used by artists to 
produce warm brown tones, and were so employed by the ancient masters, who 
possessed the secret of preventing them diffusing through and discoloring the light- 
colored paints in juxtaposition. 



BITUMINOUS ENAMELS 

These are prepared from bituminous varnishes by grinding in dry 
pigments sufficientiy intense to overcome the inherently daik color of 
the varnish. Th3 enamels at best can be manufactured in compara- 
tively dark hues only, which limit their scope of usefulness. They have 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 477 

the advantages of extreme durability and low cost, since bituminous 
materials are less expensive than the resins otherwise used for this purpose. 
The bituminous varnishes to be used for manufacturing enamels are 
made as translucent as possible to favor the color of the pigment. Bitu- 
minous substances showing a brown streak are accordingly selected, and 
combined with substantial amounts of resinous and oily bodies. Gil- 
sonite constitutes the most popular base, since it shows the optimum 
brown color, possesses the necessary hardness, and at the same time 
does not tend to gelatinize with lead, zinc and chromium pigments. 

The pigments are incorporated in the vehicle by grinding through a paint mill, p. 469. 
The following pigments may be used: 

Red iron oxide to produce deep reds and maroons. 
Chrome green to produce deep shades of green and oh've. 
Yellow ochre to produce browns. 
Chrome yellow to produce deep yellows and browns. 

Lithopone, zinc white, white lead and subUmed lead to produce tans (without 
other additions). 

Graphite used either alone or in combination with lampblack or carbon black 
for coating structural steel, and metal roofs. 

BITUMINOUS JAPANS 

In this treatise the term/' japan " is used to designate a dark-colored 
menstruum applied to metals, wood, fabrics, etc., intended to be hardened 
by haking. Japans are sometimes used for impregnating felted or woven 
fabrics for electrical insulating purposes. In composition they fall into 
an}^ of the four groups enumerated on p. 462, the fillers and pigments 
being omitted. The base of cheap japans is composed solely of bitu- 
minous materials blended in the proper proportions, whereas the better 
grades are made from mixtures of bituminous materials and vegetable 
drying oils, with or without the addition of resin. They are opaque 
black to translucent brown in color, and after baking, form coatings 
which are extremely hard, tough and resistant to abrasion. 

Japans are often made from semi-soHd native asphalts, and in some cases resid- 
ual asphalts derived from aromatic-base petroleum having the property of harden- 
ing on "baking." Toughness may be imparted by fluxing with a small percentage 
of blown peti oleum asphalt or fatty-acid pitch. Fatty-acid pitches which have been 
over-heated in their process of manufacture, are especially suitable for this purpose 
being often used alone. The characteristics of bituminous substances suitable 
for manufacturing japans are as follows: 

(1) They must be homogeneous and free from any fine particles of grit. 

(2) They should show a black streak, and be opaque when viewed in a thin 
layer. 



478 ASPHALTS AND ALLIED SUBSTANCES 

(3) They must not separate, curdle or " gelatinize " on thinning with petroleum 
naphtha. 

(4) They must bake in a reasonable length of time to a tough and permanently 
glossy coating, without shrivelling or " crazing." 

A popular form of japan consists of gilsonite fluxed with a fatty-acid pitch of 
the type described, and thinned with petroleum naphtha to brushing consistency. 
If the fatty-acid pitch does not bake sufficiently rapid, a common scheme consists 
in combining a small percentage of dryer such as manganese dioxide or raw umber, 
at a temperature of 450° F. Tougher and more elastic japans are prepared by 
incorporating a proportion of bodied Unseed oil, which also serves to improve the 
gloss. 

Since semi-drying vegetable and animal oils will oxidize to tough coatings at 
elevated temperatures, and are usually less expensive, they may be substituted for 
the vegetable drying oils, especially if bodied and combined with dryers. Thus 
cottonseed oil, corn oil, soya bean oil, and fish oil have been used for this purpose, 
sometimes combined with a small percentage of china-wood oil to accelerate the 
drying. Another expedient consists in bodying the vegetable oils at 450-475° F. 
with a small proportion of Prussian blue (^-1 ounce per gallon), which serves to 
convert the oil into a brownish black liquid, thus increasing the opacity of the japan, 
and at the same time imparting drying properties to the oil. This is the same 
procedure followed in manufacturing baking varnishes and japans for the patent- 
leather industry. 

Japans are applied to articles by dipping, brushing or spraying, and heated in 
specially constructed ovens from 1-4 hours at 200-400° F. depending upon their 
composition. Modern practice favors the use of higher temperatures for shorter 
periods of time. Wooden and other porous articles must be baked longer than 
metal. Semi-glossy and flat black japans are prepared by grinding carbon- or 
lampblack in the foregoing menstrua, and when baked present a surface simulating 
the appearance of hard rubber. Sometimes a small percentage ^^ oxi«." ' zinc 
is incorporated to impart a grayish cast. Baked japans form a harder, tougher and 
more weatherproof coating than those resulting from bituminous varnishes allowed 
to air-dry at room temperature.^ 

Japans containing 10-17 gal. of drying oil per 100 lbs. of sohd constituents 
are employed for insulating armature and field coils of motors and dynamos, also 
transformer and magnet coils, in small plants where vacuum impregnating apparatus 
is not available (p. 449). The coils after having been woimd with cotton or other 
fibrous material are heated in an oven until the moisture has been expelled, and 
while still hot are dipped into the cold japan. After removing and allowing the 
excess to drain, the coils are baked in an oven at 180-200° F., usually from 8-12 
hours. It is advisable to dip and bake the coils twice to insure thorough impreg- 
nation. These japans are sold under the trade name of " bl' ^«king varnish." 
and if properly prepared will withstand an alternating current having a potential 
of 800-1000 volts per mil, after having been baked 300 hours. One of the essential 
characteristics of the "varnish" is that it shall neither soften nor become brittle when 
applied to armatures of dynamos or motors subjected to continual vibration, and 
often becoming heated as high as 190° F. in service. Should the varnish or japan 

i"The Application of Gas to Japaning and Lacquering," by E. F. Davis, published by the 
National Commercial Gas Association, Brooklyn, N. Y., 1916. 



BITUMINOUS PAINTS, CEMENTS AND VARNISHES 479 

become brittle, the vibration will soon cause it to crack and pulverize, and result 
in short-circuiting the machine. This is one of the severest tests to which any 
form of varnish is subjected. It reouires considerable skill to prepare a japan 
that will retain its pliability on long service when subjected to alternate heating 
and cooling in contact with air, combined with the vibrating and centrifugal action 
exerted by the revolving armature. A simple test consists in baking the japan 
on a small strip of muslin at 195° F. for 300 hours, and then observing whether it 
can be bent double (fiat on itself) without cracking at 77° F. It must also with- 
stand continuous immersion in hot lubricating oil without softening or disinte- 
grating. 

Resins are sometimes added to the baking japans, but are not looked upon with 
favor because of their tendency to make the coating brittle. 



PART V 
METHODS OF TESTING 



CHAPTER XXVIII 
PHYSICAL CHARACTERISTICS 

Chapters XXVIII, XXIX, XXX and XXXI will be devoted to a 
description of the most important tests used for examining crude, refined 
and blended bituminous substances. Certam of the tests have been 
adopted as standards by technical societies, and particularly the American 
Society for Testing Materials, whose committees have been active in 
this field, accomplishing much to clarify what formerly constituted a 
veritable jumble of rule-of -thumb methods. Other tests appearing in 
the current literature will be included where they have been found 
adequate, but in certain cases these have been amplified or elaborated 
to conform with the practice followed in the author's laboratory. The 
author, however, assumes full responsibility for any methods described 
which have not been proposed or adopted as '' standard." 

The tests which follow are grouped under four headings, viz., physi- 
cal characteristics, heat tests, solubility tests and chemical tests, a 
chapter being devoted to each. In general, a test may have one or 
more objects in view, viz.: 

(1) Serving as a means of identification. 

(2) Ascertaining the value of the substance for a given use. 

(3) Gauging the uniformity of its supply. 

(4) An aid to factory control in its manufacture, refining or blend- 
ing, and 

(5) As a criterion of its quality. 

The last named may serve as an indication of its purity, the care 
exercised in its preparation, or its intrinsic value. The tests pertain- 
ing to bituminous substances fulfil these requirements as shown in 
Table XXXIV. 

480 



PHYSICAL CHARACTERISTICS 



481 



TABLE XXXIV 



Description, 



For 
Pur- 
poses 

of 
Identi- 
fication. 



Adapti- 
bility 
for a 
Given 
Pur- 
pose. 



Gaug- 
ing the 

Uni- 
formity 

of 
Supply. 



Pur- 
poses 
of 
Factory 
Control 



As a 
Cri- 
terion 
of the 
Qual- 
ity.* 



Physical Cliaracleristics : 

Color in mass 

Homogeneity 

Appearance surfaced aged one week . 

Fracture 

Lustre 

Streak on Porcelain 

Specific grfivity 

Viscosity 

Hardness or consistency 

Susceptibility factor 

Ductility 

Tensile strength 

Adhesiveness 



Heat Tests: 

Odor on heating 

L^pon subjecting to heat. . 

Fusing-point 

Volatile matter 

Flash-point 

' Burning-point 

Fixed carbon 

Distillation test (.for tars). 



Solubility Tests: 

Solubility in carbon disulphide 

Carbenes 

Solubility in 88° petroleum naphtha 
Solubilitv in other solvents 



Chemical Tests: 

Water 

Carbon 

Hydrogen 

Sulphur 

Nitrogen 

Oxygen 

Free carbon in tars 

Naphthalene in tars 

Solid paraffines 

Saturated hydrocarbons. . . . 

Sulphonation residue 

Mineral matter 

Saponifiable constituents. . . 

Asphaltic constituents 

Unsaponifiable matter 

Glycerol ; 

Diazo reaction 

Anthraquinone reaction. . . . 
I-iebermann-Storch reaction . 



YES 
YES 
Yes 
YES 
Yes 
YES 
YES 



YES 
Y^ES 



YES 
YES 
YES 
Y''es 



YES 
Yes 



YES 
Yes 
YES 
Yes 



Y'es 
YES 
YES 
Y^ES 
Y'ES 
YES 
Y^ES 
YES 
Y'ES 
YES 
YES 
YES 
Y'ES 
YES 
YES 
YES 
YES 
YES 
YES 



Yes 
YES 

YES 
Y'es 

YES 
YES 
YES 
YES 
YES 
YES 



YES 
Y^ES 
YES 
YES 

YES 



YES 



Yes 
YES 



Yes 



YES 



Yes 



Yes 
Yes 
YES 
Y^ES 
Yes 



YES 
Y'es 

Yes 



Yes 



YES 
Yes 
Yes 



Yes 



YES 
Y''es 



Ye> 



Yes 



Yes 
Y'es 
YES 
YES 
Yes 



YES 
Y'es 
Yes 



Yes 



Yes 

Y'es 



Y'es 



YES 
YES 



YES 



YES 



YES 
YES 



YES 



YES 
YES 



YES 



(a) Purity; (b) Care exercised in its preparation; (c) Intrinsic value. 



482 



ASPHALTS AND ALLIED SUBSTANCES 



TABLE XXXV.— SYNOPTICAL TABLE OF THE MOST IMPORTANT 



Non-asphaltic petroleum. 
Mixed-base petroleum. . . 
Asphaltic petroleum 



Ozokerite 

Montan wax. . 
Paraffine wax. 



Native asphalts (contg. less than 
10% mineral matter) 

Native asphalts (contg. greater than 
10% mineral matter) 

Residual oils 

Blown petroleum asphalts 

Residual asphalts 

Sludge asphalts 

Wurtzilite asphalt 



Gilsonite .... 
Glance pitch. 
Grahamite. . . 



Conch. 
Cone, to H 
Cone, to H 



Cone, to H 

Conch. 
Cone, to H 



Variable 
Variable 



Variable 
Conch. 
Conch. 
Conch. 



Wh. to Yel, 
Yel. 
Wh. 



Bn. to Bk 
Bn. to Bk 

Bn.'to Bk. 

Bk. 

Bk. 
Bn. to Bk, 



0.95-1 

0.85-1 

0.90-1 

1.00-1 

1.05 

1.04 



Bn. 
Bk. 
Bk. 



f^^ 



w)!2;* 



0.75-0.90 
. 80-0 . 95 
0.85-1.00 



0.85-1.00 
0.90-1.00 
0.85-0.95 



0.95-1.12 



15 
05 
07 
17 
1.20 
1.07 



1.05-1.10 
1.10-1.15 
1.15-1.20 



CO. 



Liquid 
Liquid 
Liquid 



20-40 
>100 
15-80 



0-> 100 

5-> 100 

0-7 
2-30 
5-100 
5-100 
20-50 



90-120 
90-120 
>150 



'■+3 +j 

Q, to 



>80 

>100 

>100 



15-> 100 
30- > 100 



8-40 
40-60 
40-60 
30-40 



>100 
>100 
>100 



Elaterite 

Wurtzilite 

Albertite 

Impsonite 

Asphaltic pyrobituminous shales. , 



Cone, to H 

Cone, to H 

Hackly 

Conch. 



Bn. 
Bn. 
Bn. to Bk. 
Bk. 
Var. 



0.90-1.05 
1.0.5-1.07 
1.07-1.10 
10-1.25 
1 . 50-1 . 75 



Rubbery 
>150 
>150 
>150 
>150 



Peat (dry) 

Lignite (dry) 

Bituminous coal 

Anthracite coal 

Non-asphaltic pyrobituminous shales 



Wax tailings 

Oil-gas tar 

Oil-gas-tar pitch . . . 

Water-gas tar 

Water-gas-tar pitch , 



Variable 
Variable 

Hackly 
Cone, to H 

Conch. 



Bn. 
Bn. 

Bn. to Bk. 
Bk. 
Var. 



0.15-1.05 
00-1 . 25 
20-1.40 
30-1 . 60 
30-1 . 75 



>150 
>150 
>150 
>150 
>150 



Conch. 



Conch. 



Yel. 
Bk." 
Bk.' 



00-1 . 10 
0.95-1.10 
1.15-1.30 
1.05-1.15 
1 . 10-1 . 20 



5-20 


10-100 


10-100 



20-40 
'>100 

>'io'o 



Pine tar 

Pine-tar pitch 

Hardwood tar 

Hardwood-tar pitch . 
Rosin pitch 



Conch. 



Bn. 



Conch. 
Conch. 



Bn. to Bk. 
Yel. to Bn. 



1 . 05-1 . 10 
10-1.15 

1 . 10-1 . 20 
20-1 . 30 

1.08-1.15 




10-100 


10-100 
50-100 



>100 



>100 
>100 



Peat tar 

Peat-tar pitch. . . 

Lignite tar 

Lignite-tar pitch. 
Shale tar 



Conch. 
Conch. 



Bn. to Bk. 
' ' Bk.' ■ ' 



0.90-1.05 
05-1.15 

0.85-1.05 
05-1 . 20 

0.85-0.95 




10-100 


10-100 





>100 

'> lo'd 



Gas-works coal tar. 

Gas-works coal-tar pitch . . . 

Coke-oven coal tar 

Coke-oven coal-tar pitch. . . 
Blast-furnace coal tar.. .... 

Blast-furnace coal-tar pitch. 

Producer-gas coal tar 

Producer-gas coal-tar pitch. 



Conch. 
Conch. 



Bk. 
'Bk.' 



Conch. 
Conch. 



Bk. 



Bk. 



Bone tar 

Bone-tar pitch. . 
Fatty-acid pitch , 



Conch. 
Variable 



Bk. 
Yel. to Bk. 



1.15-1.30 
1.15-1.40 
10-1.30 
20-1.35 
i. 15-1.30 
1 . 20-1 . 30 
1.15-1.30 
1.20-1.35 




10-100 


10-100 


10-100 


10-100 



>100 

'>i'o"o' 



>100 

'>i'o'o' 



0.95-1.05 
1.10-1.20 
0.90-1.10 





10-100 

0-40 



75-100 
8-40 



PHYSICAL CHARACTERISTICS 



483 



DISTINGUISHING CHARACTERISTICS OF BITUMINOUS SUBSTANCES 





C! 








c^ 






% 






c? 




o 














r3 


Lh 




■* 




JH 






Ol 


■*^ 


u 


^ 


"n 








It 

C3'-' 


6 






? 

H 






M 

H 


C . 




^ 


3 


O^ 




.^ — +i 


— ' -t-J 





-^ 


- <-■ .to 


c 


C-ko 


^v. ^ 


K^ 


c -^ 






2 




^ 



3 rt 


§ s £ 
Sit 





lb 


f 


0% 

s 


< 


% 


% 


% 


% 


% 


% 


% 


% 


% 


% 






M-2 


98-100 


0-H 


0-2 


0-H 


98-100 


0-2 


10-25 


90-100 


0-2 


No 


No 


2-5 


98-100 


0-1 


0-2 


0-1 


95-100 


0-3 


3^-10 


85-95 


0-2 


No 


No 


5-10 


98-100 


0-1 


0-2 


0-1 


90-100 


0-5 


0-Tr. 


80-95 


0-5 


No 


No 


H-10 


95-100 


0-1 


0-5 


0-3 


75-95 


0-2 


50-90 


90-100 


0-2 


No 


No 


2-10 


98-100 


0-2 


0-2 


0-2 


80-100 


3-6 


0-10 


0-10 


50-80 


No 


No 


0-2 


99-100 


0-M 


o-y2 





99-100 


0-Tr. 


95-100 


95-100 





No 


No 


1-25 


60-98 


0-40 


0-10 


0-5 


25-95 


0-2 


0-5 


90-100 


0-2 


No 


No 


5-25 


Tr.-90 


0-25 


10-95 


0-5 


Tr.-85 


0-2 


0-5 


90-100 


0-2 


No 


No : 


2-10 


98-100 


0-3/2 


O-H 


0-1 


80-99 


0-3 


0-15 


90-100 


Tr.-5 


No 


No 


5-20 


95-100 


0-5 


0-H 


0-10 


50-90 


2-5 


0-10 


90-100 


Tr.-2 


No 


No 


5-40 


85-100 


0-15 


0-1 


0-30 


25-85 


0-2^ 


0-5 


90-100 


0-2 


No 


No 


5-30 


95-100 


0-5 


0-1 


0-15 


60-95 


3-7 


0-M 


80-95 


0-2 


No 


No 


5-25 


98-100 


0-H 


Tr.-2 


0-2 


50-80 


0-2 


0-Tr. 


90-95 


Tr. 


No 


No 


10-20 


98-100 


0-1 


Tr.-l 


0-1 2 


40-60 


0-2 


0-Tr. 


85-95 


Tr. 


No 


No 


20-30 


95-100 


0-1 


Tr.-5 


0-1 


20-50 


0-2 


0-Tr. 


85-95 


Tr. 


No 


No 


30-55 


45-100 


0-5 


Tr.-50 


0-80 


Tr.-50 


0-2 


0-Tr. 


80-95 


Tr. 


No 


No 


2-5 


10-20 


70-90 


Tr.-lO 


Tr.-2 


5-10 


1-5 


0-Tr 


80-90 


Tr.-15 


No 


No 


5-25 


5.-10 


80-95 


Tr.-lO 


Tr.-2 


Tr.-2 


0-2 


1 0-Tr. 


90-98 


Tr. 


No 


No 


25-50 


2-10 


85-98 


Tr.-lO 


Tr.-2 


Tr.-2 


0-3 


0-Tr. 


90-98 


Tr. 


No 


No 


50-85 


1-6 


90-99 


Tr.-lO 


Tr.-2 


Tr.-2 


0-3 


0-Tr. 


90-98 


Tr. 


No 


No 


2-25* 


Tr.-3 


15-70 


30-85 


0-Tr. 


0-Tr. 


0-3 


Tr.-3 


90-98 


Tr. 


No 


No 


15-35 


2-6 


15-98 


2-80 


0-2 


0-5 


26-44 






Tr.-15 


No 


No 


25-50 


2-15 


65-98 


2-25 


0-1 


5-10 


15-28 






Tr.-5 


No 


No 


35-75 


J4-2 


75-98 


2-25 


o-M 


0-1 


3-18 






Tr.-l 


No 


No 


60-90 


0-^ 


75-98 


2-25 








1-5 









No 


No 


20-45* 


0-1 


15-70 


30-85 





0-H 


3-15 






Tr.-2 


No 


No 


2-8 


98-100 


0-2 


0-Tr. 


0-Tr. 


95-100 


0-2 


Tr.-o 


90-100 


Tr. 


No 


Yes 


10-25 


98-100 


0-2 


0-1 


0-2 


50-85 


1-2 


0-5 


20-40 


Tr. 


Yes 


Yes 


20-30 


85-98 


2-15 


0-1 


2-20 


65-85 


0-2 


0-5 


20-40 


0-1 


Yes 


Yes 


10-20 


98-100 


0-2 


0-1 


0-2 


20-75 


1-2 


0-5 


0-15 


Tr.-2 


Yes 


Yes 


25-40 


85-98 


2-15 


0-1 


2-15 


50-80 


0-2 


0-5 


0-15 


0-1 


Yes 


Yes 


5-15 


98-100 


0-2 


0-1 


0-2 


65-95 


5-10 





Tr.-5 


10-50 


Yes 


No 


10-25 


40-95 


2-60 


0-1 


0-5 


25-80 


2-8 





Tr.-3 


10-40 


Yes 


No 


5-20 


95-100 


0-5 


0-1 


0-2 


50-90 


2-10 





Tr.-5 


5-25 


Yes 


No 


15-35 


30-95 


5-70 


0-1 


2-10 


15-50 


1-0 





Tr.-5 


5-25 


Yes 


No 


10-20 


98-100 


0-2 


0-1 


0-5 


90-100 


5-10 





Tr.-5 


25-95 


Yes 


No 


5-15 


98-lOC 


0-2 


0-1 


0-2 


95-100 


5-15 


5-15 


5—15 


5-15 


Yes 


No 


10-30 


95-99 


0-5 


0-1 


0-5 


65-95 


2-8 


2-5 


5-10 


0-5 


Yes 


No 


5-20 


98-100 


0-1 


0-1 


0-2 


95-100 


5-10 


10-25 


10-20 


5-20 


Yes 


No 


10-40 


95-99 


0-2 


0-1 


0-5 


75-95 


2-5 


1-5 


5-15 


0-5 


Yes 


No 


5-10 


98-100 


0-2 


0-1 


0-2 


95-100 


1-5 


5-15 


15-35 


0-2 


Yes 


No 


15-40 


60-95 


5-40 


0-1 


0-2 


20-40 


1-3 





0-5 


2-5 


Yes 


Yes 


30-45 


55-90 


10-45 


0-1 


2-10 


lC-30 


Tr.-2 





0-5 


Tr.-l 


Yes 


Yes 


15-40 


80-97 


3-20 


0-1 


0-2 


20-40 


1-3 





0-5 


2-5 


Yes 


Yes 


20-45 


60-85 


1^40 


0-1 


2-10 


10-30 


Tr.-2 





0-5 


Tr.-l 


Yes 


Yes 


5-25 


65-80 


10-25 


10-15 


0-2 


15-35 


1-3 





5-20 


2-5 


Yes 


Yes 


10-30 


50-75 


15-35 


10-20 


2-10 


5-25 


Tr.-2 





5-20 


Tr.-l 


Yes 


Yes 


10-35 


75-90 


10-25 


0-2 


0-2 


20-40 


1-3 





0-5 


2-5 


Yes 


Yes 


25-45 


60-85 


15-40 


0-2 


2-10 


10-30 


Tr.-2 





0-5 


Tr.-l 


Yes 


Yes 


5-15 


95-100 


0-5 


O-Tr. 


0-2 


95-lOC 


2-8 





0-5 


5-40 


Yes 


No 


15-25 


85-95 


1-15 


0-Tr. 


0-10 


75-95 


0-2 





0-5 


2-25 


Yes 


No 


5-35 


95-100 


0-5 


0-5 


0-5 


80-100 


2-10 


Tr. 


0-5 


5-98 


No 


No 



* Calculated 00 mineral-free basis, 



484 ASPHALTS AND ALLIED SUBSTANCES 

Table XXXV contains a list of the principal bituminous substances, together with 
such physical and chemical tests as will enable them to be distinguished one from 
another. Under each heading the minimum and maximum figures are included, 
based on the author's experience. His intention has been to make the range suf- 
ficiently liberal to cover all the commercial varieties, and at the same time prevent 
the range being too broad, since this would result in unnecessary overlapping. 

Test 1. Color in Mass. This test is used largely for purposes of 
identification, and consists in examining a freshly prepared surface of 
the bituminous material in daylight. The colors range from white, 
through the various shades of yellow, brown and black. Some possess 
a greenish or reddish cast, and again others may appear fluorescent. 
Purified mineral waxes appear pure white, wax tailings a bright yellow, 
asphalts and pitches are generally brownish black, grayish black or 
black. 

Test 2. Homogeneity. This test is used for purposes of identifica- 
tion, for determining the adaptability of the bituminous substance to a 
given purpose, for gauging the uniformity of supply, for purposes of 
factory control, as a rough criterion of the purity, and when the bitu- 
minous mixture is free from mineral and carbonaceous matter, for 
ascertaining whether a complete amalgamation of the constituents occur, 
especially after fluxing (p. 343). 

Test 2a. Homogeneity to the Eye at 77° F. With soft materials this may be 
ascertained by disturbing a freshly prepared surface of the material (cooled to room 
temperature) with a rod or spatula, and observing whether any dulling occurs. 
An alternate method consists in drawing a small pellet into a thread between the 
fingers, and noting whether it duUens while being drawn out. With hard and 
brittle substances a freshly fractured surface may be examined. Any evidence of 
dullness is an indication of: (1) the presence of mineral matter, (2) the presence 
of free carbon (non-mineral matter insoluble in carbon disulphide), (3) an imper- 
fect blending of the bituminous constituents. 

Test 2b. Homogeneity under Microscope. This is ascertained by spreading a 
minute quantity of the bituminous material on a microscope slide in a thin layer 
and examining it by transmitted light under a magnification of 100 to 250 diam- 
eters. With hard bituminous materials, the sHde should be warmed and the 
specimen spread uniformly and thinly, while melted. This test manifests the same 
characteristics as the preceding, and in addition, permits the detection of the 
solid paraffines, which separate from the bituminous matrix in crystal-like masses, 
Paraffine may be identified positively under a microscope equipped with a polariscopic 
attachment. 

Test 2c. Homogeneity When Melted. This constitutes a rough test for detect- 
ing the presence of substantial amounts of extraneous matter, such as mineral con- 
stituents or free carbon. The bituminous material is simply melted and stirred with 
a rod. If these constituents are present in large quantities, they will impart a gritty 
feel to the mass, and will often settle out on standing. 



PHYSICAL CHARACTERISTICS 485 

Test 3. Appearance Surface Aged Indoors one Week. A small 
quantity of the bituminous material is carefully melted at the lowest 
possible temperature and poured into a tin ointment box or deep seam- 
less can as used for determining the volatile matter (Test 16). The sur- 
face should be free from froth or bubbles and allowed to cool in a place 
free from draughts. When cool, the surface is examined, and then cov- 
ered to protect it from dust. At the end of a week the cover is 
removed and the surface re-examined. If bright and lustrous, it will 
indicate a perfect amalgamation of the constituents, also the absence 
of oily, greasy and undissolved constituents. A lustreless surface is 
an indication of the presence of extraneous mineral or carbonaceous 
matter, or evidence that the constituents do not blend or amalgamate 
properly. If the surface appears greasy or wax-like, vaseline- or paraf- 
fine-like bodies are present, since these have the property of separating 
or '' sweating '' from the bituminous matrix on standing. This would 
prove objectionable where the bituminous material is to be used for 
surfacing prepared roofings dusted with talc, or for manufacturing 
bituminous paints, varnishes or japans. This test is accordingly 
used for purposes of identification, determining the adaptability 
of the substance for a given purpose and as a criterion of its 
quality. 

Test 4. Fracture. This is ascertained upon cleaving the specimen 
by subjecting it to a sharp blow, and examining the cleavage surface. 
Only hard and " brittle " bituminous substances will yield to this test, 
including the hard asphalts and asphaltites. The fracture may either 
appear conchoidal (rounded and curved hke a shell), or hackly (jagged, 
irregularly and rough). 

Test 5. Lustre. This indicates the manner in which light is re- 
flected from a freshly fractured surface, and may be bright or vitreous — 
indicating that it has the brilliancy or shine of glass; greasy — indicating 
that it presents an oily or greasy surface; waxy— indicating that it 
has the characteristic appearance of wax; or dull — indicating that the 
surface is without lustre. These manifestations are used for purposes 
of identification, and for determining the adaptability of the bituminous 
material for manufacturing paints, varnishes and japans. 

Test 6. Streak on Porcelain. This represents the color of the pow- 
der which is left beh'nd on drawing a piece of the solid bituminous 
material across the surface of ungiazed porcelain. Hard bituminous 
materials only will yield to this test. The streak may be classified as 
white (where no streak is visible), yellowish, yellowish brown, brown, 
brownish black and black. This test is of value for purposes of identi- 



486 



ASPHALTS AND ALLIED SUBSTANCES 



fication, and as an indication of the suitability of the substance for use 
with colored pigments. 

Test 7. Specific Gravity. This test is of value (1) in identifying 
bituminous materials; (2) for controlling the uniformity of supply, 
(3) for purposes of factory control, (4) for figuring the weight of a given 
volume as delivered in tank cars, when stored in tanks or else upon 
filling into containers, (5) for calculating the volume of the bituminous 
binder in pavements (p. 364). The specific gravity is of special value 
when considered in connection with the fusing-point (p. 293) or hard- 
ness. 



y 



llS 



Shot 
From A. S. T. M. Standards. 

Fig* 153. — Hydrometer. 



Test 7a. Hydrometer Method for Fluid Materials. Where speed is essential 
and great accuracy not required, the specific gravity of fluid bituminous materials 
may be determined with a hydrometer having its scale 
sub-divided to unity in the third place of decimals. 
Usually a series of hydrometers are used, ranging respec- 
tively from 0.800 to 0.900, 0.900 to 1.000, 1.000 to 1.080, 
1.070 to 1.150, 1.150 to 1.230, and in such dimensions 
as to enable them to be used in a 100 c.c. cylinder 300 
mm. long (with a permissible variation of 30 mm.) and 32 
mm. in diameter (with a permissible variation of 3 mm.). 
The hydrometer should be of the form shown in Fig. 
153, and have the following dimensions: length of stem 
125 mm. (±12.5 mm.), length of bulb 105 mm. (±10.5 
mm.), length of scale 80 mm. (±8.0 mm.), diameter of 
stem 6 mm. (±0.5 mm.), diameter of bulb 22 mm. 
(±2.0 mm.).i 

Most hydrometers are adapted to read at 60° F./60° 
F., or in other words, the instrument is calibrated for 
water at 60° F. taken as unity. The standard tempera- 
ture for testing bituminous materials is 77° F., and they should accordingly be 
brought to this temperature when tested with the hydrometer. For correcting the 
reading to water at 77° F., it should be multiplied by 1.002, as follows: 

Sp.gr. at 77° F./77°F.= Sp.gr. at 77° F./60° F.X 1.002. 

In running the test, the bituminous material is brought to a temperature of 
77° F., immediately poured into the hydrometer jar, and then the hydrometer 
slowly allowed to sink into it until it comes to a definite resting-point, whereupon 
it is raised slightly, and allowed to sink a second time. The reading is then noted. 
The hydrometer must not be pushed below the point at which it comes to rest 
until after the second reading has been taken, then it should be pushed a slight 
distance below the end point to observe whether or not it will rise. If it fails to 
do so, it is evident that the bituminous material is too viscous to be tested by the 
hydrometer method, and some other method should be employed. Care should be 
taken that the hydrometer does not touch the sides or bottom of the cylinder when 

1" Standard Methods for Sampling and Analysis of Creosote Oil" (Serial Designation: D 38-17) of 
the Am. Soc. Testing Materials, A, S. T. M. Standards Adopted in 1917, 34. 



PHYSICAL CHARACTERISTICS 



487 



the reading is taken, also that the surface of the hquid is free from froth or 
bubbles.^ 

For converting specific gravity into degrees Baumd and vice versa, the follow- 
ing formulae may be used:^ 



For liquids hghter than water: 
°Baum6 = 



140 



Sp.gr. 60760° F. 



-130 



Sp.gr. 60760° F.= 
For liquids heavier than water: 
°Baume = 145 



140 



130+°Baum6 
145 



.gr. 60760° F.= 



Sp.gr. 60760° F. 
145 



145-°Baume 



Test 7b. Westphal Balance Method. This is also adapted to testing fluid 

bituminous materials. The instrument as suppHed by the manufacturer (Fig. 154) 

is provided with a cylinder of about 50 c.c. capacity, 

calibrated for use at 60760° F. If the test is to be 

made at 77° F., it is subject to the same correction 

as in the hydrometer method. 

The Westphal balance may be adapted for as 

Uttle as 8 c.c. of the bituminous material, by using 

a special plummet small enough to fit into a 10 c.c. 

cylinder. The plummet may be made from a piece 

of glass tubing 7 mm. outside diameter, which is 

sealed at one end with a short platinum wire fused 

into the glass. Nine to ten grams of mercury are 

placed in the tube forming a column 35-40 mm. high. 

The tube is then cut off within 20 mm. of the top 

of the mercury column, and the open end sealed with 

a blow-pipe. This plummet should measure 55-60 

mm. over all, and weigh from 10 to 12 g. If a 

represents the weight of the plummet in air, h its 

weight in water at a definite temperature, and c its 

weight in the bituminous material at the same 

temperature, then the specific gravity of the bituminous material at this tem- 

c— a 
perature = - .» 




Courtesy of Eimer & Amend. 

Fig. 154.— Westphal Balance. 



1 Bulletin No. 314, U. S. Dept. of Agr., Wash., D. C. Dec. 10, 1915; "Laboratory Manual ol 
Bituminous Materials," by Provost Hubbard, p. 30, N. Y., 1916; "Specific Gravity — its Determina- 
tion for Tars, Oils and Pitches," by .J. M. Weiss, J. Ind. Eng. Chem., 7, 21, 1915. 

2 Circular No. 19, Bureau of Standards, "Standard Density and Volumetric Tables," Wash., 
D. C, 1916; Circular No. 59 Bureau of Standards, "U. S. Standard Baum6 Hydrometer Scales," 
Wash., D. C, 1916. 

3 "Standard Methods for Sampling and Analysis of Creosote Oil" (Serial Designation: D 38-17) of 
the Am. Soc. Testing Meterials, A. S. T. M. Standards Adopted in 1917, 40. 



488 ASPHALTS AND ALLIED SUBSTANCES 

Test 7c. Pycnometer or Specific-Gravity Bottle Method. Several forms of glass 
bottles are used for this purpose, with a ground-glass stopper having a small verti- 
cal hole bored through to enable it to be completely filled with the bituminous 
material. These are made in various sizes. 

An improvised form which may be used to good advantage when a small quan- 
tity of liquid bituminous material is available, consists of a 1 c.c. pipette, and a glass 
tube sealed at one end, the inside diameter of which is shghtly larger than the out- 
side diameter of the lower stem of the pipette. On using this instrument, the liquid 
is first brought to a definite temperature, then sucked to the upper mark of the 
pipette by means of a piece of rubber tubing temporarily attached to its upper 
stem. The outside is carefully wiped dry and the lower stem inserted in the glass 
tube which serves to retain any hquid which may drain from the pipette. A small 
piece of wire twisted about the pipette near the top is formed into a ring to hang 
it from the hook above the balance pan. The pipette is thus supported in a verti- 
cal position and weighed.^ 

If a represents the weight of the pipette with glass tube empty, 6 its weight 
filled with water at a definite temperature, and c its weight filled with the bitumi- 
nous material at the same temperature, then the specific gravity may be calculated 
from the following formula: 

c—a 
b—a 

It is customary to determine the specific gravity of bituminous materials at 
77°/77* F., although in special instances it is expressed at 6()°/60° F., and in the 
case of creosote oil at 100 "/GO" F. For converting the specific gravity of a sub- 
stance found at a higher temperature to the standard temperature (lower), the 
following formula should be used: 

Sp.gr. Substance at <i/^i = Sp.gr. Substance at t2/ti+k{t2—ti). 
in which ti= the temperature at which the specific gravity of the substance was 
determined, 

<i= the temperature (lower) at which the specific gravity of the substance 
is to be calculated, and 

k= the coefficient of expanison, which is constant for any particular substance. 

If perchance the specific gravity of the substance has been compared wdth that 
of water at a higher temperature, then to convert it to a lower temperature com- 
pared with water at the same temperature, the following formula should be used:^ 
Sp.gr. Substance at ii/<i = Sp.gr. Substance at i2A2XSp.gr. Water at to/ti-]-k(t2-td' 

In both of the above formulae, the following values may be taken approximately 
for k, representing the coefficient of expansion per ° F. 

Creosote oil from coal tar 0. 00044 

Residual oil 0.00040 

Coal tar 0.00038 

Coke-oven tar 0.00033 

Semi-solid asphalt . 00030 

Semi-solid coal-tar pitch 0.00030 

'"Specific Gravity — Its Determination for Tars, Oils and Pitches," by J. W. Weiss, loc. cit. 
2 For the Specific gravity of water at varying temperatures, see Bureau of Standards, Circular 
No. 19, p. 43, Mar. 30, 1916. 



PHYSICAL CHARACTETISTICS 489 

The pycnometer method may also be used for finding the specific gravity of 
hard and brittle bituminous substances, including hard asphalts of high fusing-point, 
asphaltites, asphaltic pyrobitumens, non-asphaltic pyrobitumens and pyrobituminous 
shales. Approximately 3.5 grams of the material ground to 60-mesh are carefully 
weighed and introduced into a 50-c.c. pycnometer, with about 30 c.c. of distilled 
water. A vertical condensing bulb is attached to the pycnometer with a small 
section of rubber tubing, the open end being connected with an aspirator to main- 
tain a partial vacuum. The pycnometer is then boiled on a water bath to expel 
all the air from the sample. The inside of the condensing tube is then washed 
back into the pycnometer, which is cooled to the desired temperature, stoppered, 
filled to the mark with v/ater at the same temperature and weighed. The specific 
gravity may then be calculated from the following fonimla: 

(c-a) 



{b-a)-id-c) 



Where a represents the weight of the pycnometer empty, b its weight filled with 
water, c its weight containing the bituminous substance, and d its weight containing 
the bituminous substance also filled to the mark with water. ^ 

Test 7d. Sommer Hydrometer Method. This method is adapted to readily 
fusible semi-solid to solid bituminous substances. The apparatus is illustrated in 
Fig. 155 and consists of the small metal cup a holding exactly 10 c.c, a sleeve h 
threaded on the inside so that it may be attached to the top of the cup, the cover 
c and the threaded flange d. The cup with the sleeve screwed in place is filled 
with the melted bituminous substance, and heated a short time shghtly above its 
fusing-point to release any air bubbles or traces of moisture. The cup is then 
allowed to cool to 77° F., and the sleeve unscrewed. If the bituminous material 
is hard, the sleeve should first be warmed with a Bunsen burner. The bituminous 
material extending over the cup is cut off and levelled with a hot knife, the cover 
and flange fastened in place, and the specific gravity determined by suspending 
the cup from the special hydrometer illustrated. The specific gravity is read directly 
and is accurate to the third decimal place. ^ 

Test 7e. Hubbard Pycnometer Method. This method is similarly adapted to 
semi-soUd or solid bituminous materials melting under the influence of heat. The 
pycnometer is illustrated in Fig. 156 (A and B) which shows two approved forms. 
It consists of a fairly heavy straight-walled glass tube, 70 mm. long and 22 mm. 
in diameter, having a neck ground to receive a glass stopper provided with a vertical 
opening running through its entire length, having a mark etched to indicate a capa- 
city of 24-25 c.c. The bituminous material is melted and carefully poured into the 
dry pycnometer fiUing it about half full. After coohng to 77" F. it is weighed, 
then filled with water to the mark and reweighed. The specific gravity may be 
calculated from the formula given under test 7c (procedure for testing solid bitu- 
minous materials).^ 

1" Methods of Analyzing Coal and Coke," Technical Paper No. 8, Bureau of Mines, Waah., 
D. C, p. 37, 1913. 

2 "A New Method and Apparatus for the Determination of the Specific Gravity of Semi-solid 
Substances," by Albert Sommer, Proc. Am. Soc. Testing Materials, 9, 602, 1909. 

3 Bulletin No. 314, U. S. Dept. of Agriculture, Wash., D. C, p. 5; "Laboratory Manual of 
Bituminous Materials," by Hubbard, p. 34, 1916; "Methods for Testing Coal Tars and Refined 
Tars, Oils and Pitches Derived Therefrom," by S. R. Church, /. Ind. Eng. Chem., 3, 228, 1911; 
5, 195, 1913. 



490 



ASPHALTS AND ALLIED SUBSTANCES 



Test 7f. Weiss' Specific Gravity Pan Method. This method is both rapid 
and convenient, being adapted principally to semi-solid or solid bituminous products. 
The pan as illustrated in Fig. 157 is made of platinum or nickel and weighs about 
7 grams. Its dimensions are as follows: diameter of base 20 mm., diameter of top 




(A) (B) 

Courtesy A. H. Thomas Co. 

Fig. 156. — Hubbard Pycnometer. 




I.2cm. 




Courtesy of Eimer & Amend. 

Fig. 155. — Sommer Hydrometer. 



From A. S. T. M. Standards. 

Fig. 157. — Weiss Specific Gravity Pan. 



25 mm., depth 12 mm., diameter of wire 1 mm. The melted bituminous material 
is poured into the pan without taking particular care to fill it to any prescribed 
point. It is fastened to a waxed silk thread, weighed in air and then in water at 
77° F., by suspending it from the arm of a balance. The specific gravity may be 
calculated in the following formula: 

{c-a) 



(6+c)-(a+d)* 



PHYSICAL CHARACTERISTICS 



4^1 



Where a represents the weight of the pan in air, h its weight in water, c its weight 
plus the bituminous substance in air, and d its weight plus the bituminous material 
in water. 

The pan may be readily cleaned after the test by warming it over a burner 
and pouring out as much of the bituminous substance as possible, then removing 
the balance with a solvent, and finally igniting it.^ i 

Test 8. Viscosity. This test is of value in determining the adap- 
tability of the bituminous substance for a given purpose, for gauging 
the uniformity of supply^ and for factory control work. It is used 
particularly for examining liquid to semi-liquid substances for road pur- 
poses, and may also be used to good advantage for predetermining the 
ability of semi-solid substances to saturate fabrics at elevated tempera- 
tures. 

Test 8a. Engler Method. The Engler viscosimeter is illustrated in Fig. 158, 
consisting of a cylindrical vessel a, 105-6 mm. in diameter, with a cover h and a 
convex bottom, opening into a platinum- 
lined tube c, 20 nam. long, 2.9 mm. in 
diameter at the top, and 2.8 mm. at the 
bottom. The orifice may be opened or 
closed with the wooden plunger d. Metal 
projections are fastened to the inside of the 
vessel 25 mm. from the lowest portion of 
the cylindrical side-walls and 32 mm. from 
the upper opening of the orifice. These serve 
to control the volume of bituminous liquid 
introduced, which amounts to exactly 240 c.c. 
The bituminous material is maintained at 
any desired temperature by the heating- 
bath consisting of water, glycerine or cotton- 
seed oil in the cylindrical jacket /, heated 
by the ring-burner h, and the temperature 
recorded by the thermometer e. The out- 
flow of 200 c.c. of distilled water at 68° F. 
is carefully observed. If the apparatus has 
been constructed properly, this "woU require 
50-52 seconds. 

The bituminous material is ordinarily tested at IV F. (25° C), 172'' F. (50° C), 
or 212° F. (100° C.) depending upon its consistency. The viscosimeter is filled to 
the top of the points w^th bituminous material, brought to the required temperature, 
and the time noted for 200, 100, 50 or 20 c.c. to flow through the orifice. If 100 
c.c. are allowed to flow through the instrument, the reading should be multipHed 
by 2.35 to calculate the time of flow for 200 c.c. If 50 c.c. are allowed to flow 
through, the reading should be multipHed by 5, and with 20 c.c. by 11.95 to obtain 
the time of flow for 200 c.c. These factors are constant. The specific viscosity at 

'"Specific Gravity — Its Determination for Tars, Oils and Pitches," by J. M. Weies. /. Ind. 
Eng. Chem., 7, 26, 1915; Am. Soc. Testing Materials, Standards, p. 41, 1917. _ 




WO 




Fig. 158. — Engler Viscosimeter. 



492 



ASPHALTS AND ALLIED SUBSTANCES 



t" F. compared with water at 68° F. is equal to the number of seconds for 200 
CO. of the substance to pass through at t° F. divided by the seconds for 200 fi.c. 
of water to pass through at 68° F. Tables have been worked out showing the 
factor to be used when the apparatus is filled with smaller volumes of liquid, allow- 
ing different amounts to flow through. ^ 

Test 8b. Hutchinson's Tar Tester. This is illustrated in Fig. 159. It was 
invented by John Hutchinson ^ and consists of a metal spindle 9 in. long over all, 
bearing a conical-shaped disc (C) 2 in. in diameter midway between the ends, with a 
plumb-shaped weight fastened to its lower end. The instrument is supplied with 



9 ^1^(1 

Fig. 159.— Hutchin- 
son's Tar Tester. 







From A. S. T M. Proc. 
Fig. 160.— Hubbard's 
Consistency Tester. 



three poises (D) to be used with tars of different consistency or gravity. The spindle 
bears two rings (A) and (5), 2 in. apart. 

The test is conducted by placing the bituminous material in a cyUnder at least 
9 in. high and 4 in. in diameter, filled to ^ in. of the top. The bituminous material 
is brought to exactly 77° F., the tester introduced, and the time noted for the 
spindle to sink from a to b. Poise No. 1 is recommended for tars having a specific 
gravity of 1.170-1.195, No. 2 from 1.195-1.215, and No. 3 from 1.215-1.240. 
The poises do not conform to standard weights or dimensions, and the instrument 
should not therefore be regarded as a strictly scientific one. It is used extensively 
in England.' 

Test 8c. Hubbard's Consistency Tester. This is an improvement over the 
Hutchinson Tar Tester, and is illustrated in Fig. 160. It is composed of a cir- 
cular aluminium disc A fastened to a narrow aluminium rod B, also to a hollow alumi- 
nium rod C, of greater diameter, the upper end being made solid except a small 

> Bulletin No. 314, U. S. Dept. of Agriculture. Wash., D. C, p. 7, 1915; " Untersuchung der 
Kohlenwasserstoffole und Fette." by D. Holde, Berlin, p. 136, 1913. 
aEng. Pat. No. 22,042 of 1911. 
8 "A New English Tar Tester," Good Roads, 3, 337, 1912. 



PHYSICAL CHARACTERISTICS 



493 



hole, large enough to allow the entry of the rod B, which is turn is threaded at the 
bottom and screwed into a conical aluminium weight D having a 0.1875 in. taper. 
The disc A carries 2 holes 0.04 in. in diameter, placed at opposite sides, 0.145 in. 
from the centre. The upper end of the rod B carries two scale markings, one 0.25 
in., and the other 1.25 in. above the disc A. The bottom of the rod B is filled with 
lead dust until the instrument weighs exactly 2.8 g. The bituminous substance is 
first brought to 77" F. and introduced into a jacketed cylinder, with a hemi-spheri- 
cal bottom, 3f in. deep, and 2 in. in diameter. The tester is then introduced, 
recording the time required to sink below the surface of the bituminous material 
from the lower to the upper marking on the rod B. 

A fairly constant ratio is claimed to exist between the results obtained with 
this tester and the Engler viscosity (i.e., introducing 240 c.c. into the instrument 
and noting the time of flow in seconds at 77° F. for 50 c.c. of the bituminous 




Fig. 161.— Float Tester. 

material, divided by the time for 50 c.c. of water). An Engler viscosity of 60 
corresponds to approximately 2 seconds on the Hubbard instrument, an Engler 
viscosity of 120 to approximately 4 seconds, and the Engler viscosity of 240 to 
approximately 8 seconds at 77" F.^ 

Test 8d. Float Test. This instrument is used largely for testing the viscosity 
or consistency cf semi-sohd bituminous materials used for road purposes. The 
range of the float test is hmited, and it cannot be used with very fluid bituminous 
materials or with hard solids. It accordingly fills the gap between the Engler 
viscosimeter and the Hubbard consistency tester on one hand, and the needle 
penetrometer and consistometer on the other. The test is not affected by the pres- 
ence of mineral matter or free carbon. 

The instrument is illustrated in Fig. 161. It consists of two parts, viz.: an 
aluminium saucer-shaped float, and a conical brass collar weighing exactly 50 g. 

' "A New Consistency Tester for ViscouB Liquid Bituminous Materials," by Provost Hubbard 
and F. P. Pritchard, Proc. Am. Soc. Testing Materials, 17, 605, 1917. 



494 



ASPHALTS AND ALLIED SUBSTANCES 



together. The brass collar is filled with melted bituminous material upon placing 
it against a brass plate, the surface of which has been amalgamated by treatment 
with a dilute solution of mercuric nitrate and then with mercury. After cooling, 
it is levelled, placed in water at 41° F. for 15-30 minutes along with the aluminium 
float, and then screwed into the float and immediately floated on the surface of 
water warmed to the desired temperature, with the brass collar downward. No 
standard temperature has been adopted for making this test, although 90° F. is 
recommended as the most satisfactory in testing road binders, for which the instru- 
ment is intended. Very soft materials are tested at 32° F., and hard bituminous 
substances at 122° F. or 150° F. 

As the heat is transmitted through the brass collar into the plug of bituminous 
material, the latter softens until it is forced upward and out of the collar by the 

weight of the instrument. The time elapsing between 
the placing of the float on the surface of the water, 
and when the water breaks through the plug is taken 
as a measure of the viscosity of the material under 
examination. The author has also found the float test 
of value for testing bitmuinous substances at a tem- 
perature exactly 50° F. higher than the fusing-point 
by the B. and R. method, thereby furnishing a criterion 
of the susceptibility to temperature changes (see p. 
501), also a means of distinguishing between blown 
and residual asphalts (p. 293).^ 

Test 8e. Schutte Consistency Tester. This instru- 
ment, as illustrated in Fig. 162, operates similarly to 
the float tester, with the difference, however, that the 
pressure is applied by a column of water above the 
plug of pitch. The melted bituminous material is first 
introduced into a brass collar 1 in. high and f in. in 
diameter. This is placed in water at the required 
temperature for at least 10 minutes, and then screwed 
into the tube (10| in. long). The apparatus is immersed 
in water maintained at the required temperature so the water level just covers the 
lower shoulder of the tube, which is then completely filled with water at the given 
temperature, and the time interval recorded between the fiUing of the tube and the 
displacement of the plug of bituminous material at the bottom. Check tests are 
said to agree within 5 seconds. ^ 

Test 9. Hardness or Consistency. This constitutes one of the most 
important tests for examining bituminous materials, and is employed 
for purposes of identification, considered either alone or in conjunction 
with the fusing-point; for determining the adaptability of bituminous 
materials in connection with certain proposed uses; for gauging the 

1 " Controlling the Consistency of Bituminous Binders," by C. N. Forrest, Eng. Rec, 59, 584, 
1909; /. Jnd. Eng. Chem., 1, 378, 1909; "Tentative Methods for Analysis of Creosote Oil" (Serial 
Designation: D 48-17 T) of the Am. Soc. Testing Materials A. S. T. M. Tentative Staridards, proposed 
in 1917; Proc. Am. Soc. Testing Materials, 17, Vol. I, 826, 1917. 

'"Methoda for Testing Coal Tar and Refined Tars, Oils and Pitches Derived Therefrom," 
by a. K. Church, J. Ind. Eng. Chem., 3, 229, 1911. 



Courtesy of A. H. Thomas Co. 

Fig. 162.— Schutte Viscosity 
Tester. 



PHYSICAL CHARACTERISTICS 495 

uniformity of suppl}^; and for purposes of factory control. The Moh's 
hardness scale is intended for the hardest bituminous materials, whereas 
the needle penetrometer and the consistometer have a range of useful- 
ness from semi-solids to moderately hard solids. 

Test 9a. Moh's Hardness Scale. This test has long been used for recording 
the hardness of minerals by comparing their resistance to abrasion with substances 
of knowTi hardness. Ten minerals are used in a graduated scale of units, viz.: 
(1) talc, (2) gypsum, (3) calcite, (4) fluorite, (5) apatite, (6) orthoclase, (7) quartz, 
(8) topaz, (9) sapphire and (10) diamond. A pointed fragment of the standard 
mineral is moved back and forth several times on the same Kne, a short distance 
across the surface of the bituminous material under test. If the bituminous material 
is not scratched, it is harder than the mineral used, whereas if it is scratched, it 
may be either softer or of the same hardness as the standard mineral. If it is of 
the same hardness, it will in turn scratch the surface of the standard mineral 
but if it is softer, it wiU have no effect. The first four standard minerals are used 
for this purpose, as the hardest bituminous materials encountered usually do not 
test higher than 4 on Moh's scale. 

Test 9b. Needle Penetrometer. This was originally devised by H. C. Bowen 
in 1888.^ This first crude instrument was further improved by A. W. Dow.^ The 
Dow penetrometer as simpHfied in construction by Richardson and Forrest repre- 
sents the type in use to-day,^ both forms operating on the same principle and giving 
the same readings. 

The Richardson-Forrest improved penetrometer is illustrated in Fig. 163. The 
base A may be levelled by the thumb screws B, and is attached to the standard C 
and also the platen D, which by means of a screw-shank raises or lowers the revolv- 
ing disc E, on which is placed the sample of bituminous material to be tested. The 
standard C carries a bracket F adjustable as to elevation by a thumb-screw, 
also the bracket G, which on the back carries the clock-work H timing the duration 
of the test by half-second beats, and on the front the dial J divided into 360 degrees, 
with the hand K, marking the number of degrees, each of which represents one-tenth 
millimeter of penetration measured by rack on shding gauge L, engaging in pinion 
on the shaft which actuates the hand K. The bevelled-edge mirror N adjustable 
through universal joints, serves to reflect light on the sample under test. The 
plunger acts as a brake, which holds the needle bar, representing a weight of 
50 g. together with the superincumbent M^eight in place, until pressed inward, 
which movement permits the needle and weight to act upon test-block without 
friction, and is easily operated by grasping the horns Q between two fingers and 

IS. oj M. Quarierly, 10, 297, 1889; U. S. Pat. 494,974 of Apr. 4, 1893 to H. C. Bowen; 
"Report of the Operations of the Engineer Department of the District of Columbia," p. 106, for 
1889-90; also article by Clifford Richardson in Ejig. Record of Oct. 31, 1891. 

2 "Report of the Engineer Dept. of the District of Columbia, for year ending June 30, 1898," 
p. 127, "Report of the Inspector of Asphalt and Cement of the District of Columbia for the year 
ending June 30. 1901," p. 158, by A. W. Dow; "Testing of Bitumens for Paving Purposes," by 
A. W. Dow, Proc. Am. Soc. Testing Materials, 3, 354, 1903; "Relation between Some Physical 
Properties of Bitumens and Oils," by A. W. Dow, Proc. Am. Soc. Testing Materials, 6, 497, 1906. 

3 "The Development of the Penetrometer as Used in the Determination of the Consistency 
of Semi-Solid Bitumers," by Clifford Richardson and C. N. Forrest, Proc. Am. Soc. Testing 
Materials, 7, 626, 1907; "A Further Development of the Penetrometer as Used in the Determina- 
tion of the Consistency of Semi-Solid Bitumens." by C. N. Forrest, Proc. Am. Soc. Testing 
Materials, 9, 600, 1909. 



49a 



ASPHALTS AND ALLIED SUBSTANCES 



pressing the brake-head with the thumb. M represents a weight of predeter- 
mined capacity, either 50 or 150 g. A form of penetrometer operated by an elec- 
trical timing device has also been constructed.^ A miniature penetrometer for 
portable use is illustrated in Fig. 164. 

Careful investigations have been made as to the diameter of the holder for the 
bituminous material ;2 the method of preparing the specimen ;3 the size and shape 
of the needle;* also other variable factors.^ As a result of these, the following stand- 
ard test has been adopted.^ 





Courtesy of Howard & Morse. 

Fig. 163. — Penetrometer. 



Fig. 



Courtesy of Howard & Morse 

164. — Miniature Penetrometer. 



" Penetration is defined as the consistency of a bituminous material, expressed 
as the distance that a standard needle vertically penetrates a sample of the material 
under known conditions of loading, time and temperature. Where the conditions 
of test are not specifically mentioned, the load, time and temperature are under- 



1 U. S. Pat. 512,687 of Jan. 16, 1894 to A. W. Dow and T. R. Griffith; H. W. Mahr, J. Ind. 
Eng. Chem., 6, 133, 1914. 

2 " Effect of Diameter of Bitumen Holder on the Penetration Test," by C. S. Reeve, Proc. Int. 
Assoc. Testing Materials, Sixth Congress, N. Y., XXV-3, 1912. 

^ Proc. Am. Sac. Testing Materials, 16, Part I, 306, 1916; "Revised Standard Test for Pene- 
tration of Bituminous Materials," by L. W. Page, Chem. Eng. Manuf., 24, 32, 1916. 

4 "A New Penetration Needle for Use in Testing Bituminous Materials," by C. S. Reeve and 
F. P. Pritchard, J. Agric. Research, 5, 1121, 1916. 

6 "Effect of Controllable Variables on the Penetration Test for Asphalts and Asphalt Cements," 
by Prevost Hubbard and F. P. Pritchard, J. Agric. Research, 5, 805, 1916. 

c" Standard Test for Penetration of Bituminous Materials" (Serial Designation: D 5-16), A. S. T.M. 
Standards Adopted in 1916, 530. 



PHYSICAL CHARACTERISTICS 497 

stood to be 100 g., 5 seconds and 77° F. respectively, and the units of penetration 
to indicate hundredths of a centimeter. 

" The container for holding the material to be tested shall be a flat-bottom cyl- 
indrical dish, 55 mm. (2i^ in.) in diameter and 35 mm. (If in.) deep. The 
needle for this test shall be a cylindrical steel rod 50.8 mm. (2 in.) long, having a 
diameter of 1.016 mm. (0.04 in.) and turned on one end to a sharp point having a 
taper of 6.35 mm. (j in.). The water bath shall be maintained at a temperature 
not varying more than 0.2° F. from 77° F. The volume of water shall not be less 
than 10 litres, and the sample shall be immersed to a depth of not less than 
10 cm. (4 in.) and shall be supported on a perforated shelf of not less than 
5 cm. (2 in.) from the bottom of the bath. Any apparatus which will allow the 
needle to penetrate without apprecial:)le friction and which is accurately calibrated 
to yield results in accordance with the definition of penetration, will be acceptable. 
The transfer-dish for container shall be a small dish or tray of such capacity as 
will insure complete immersion of the container during the test. It shall be pro- 
vided with some means which will insure a firm bearing and prevent rocking of the 
container. The sample shall be completely melted at the lowest possible temperature 
and stirred thoroughly until it is homogeneous and free from air bubbles. It shall 
then be poured into the sample container to a depth of not less than 15 mm. 
(f in.). The sample shall be protected from dust and allowed to cool in an atmos- 
phere not lower than 65° F. for 1 hour. It shall then be placed in the water bath 
along with the transfer dish and allowed to remain 1 hour. 

" In making the test, the sample shall be placed in the transfer dish, filled with 
water from the water bath at sufficient depth to completely cover the container. 
The transfer dish containing the sample shall then be placed upon the stand of the 
penetration machine. The needle, loaded with specified weight, shall be adjusted 
to make contact with the surface of the sample. This may be accomplished by 
making contact of the actual needle-point with the image reflected by the surface 
of the sample from a properly placed source of light. Either the reading of the 
dial shall then be noted, or the needle brought to zero. The needle is then released 
for the specified period of time, after which the penetration machine is adjusted to 
measure the distance penetrated. 

" At least three tests shall be made at points on the surface of the sample not less 
than 1 cm. (f in.) from the side of the container, and not less than 1 cm. apart. 
After each test the sample and transfer dish are returned to the water bath and 
the needle shall be carefully wiped towards its point with a clean dry cloth to 
remove all adhering bituminous matter. The reported penetration shall be the 
average of at least three tests whose values shall not differ more than 4 points between 
maximum and minimum. When desirable to vary the temperature, time and 
weight, and to provide for uniform method of reporting results when such varia- 
tions are made, the sample shall be melted and cooled in air as above directed. 
It shall then be immersed in water or brine, as the case may require, fori hour at 
the temperature desired. The following combinations are suggested: 

32° F.; 200 g. weight; 60 seconds, 

77° F.; 100 g. weight; 5 seconds, ^ 

US'* F.; 50 g. weight; 5 seconds." 

1 Inserted by author. Not included in the printed method published by the Am. Soc. Testing 
Materials. 



498 



APSHALTS AND ALLIED SUBSTANCES 



The principal shortcoming of the needle penetrometer is the fact that the read- 
ings at various temperatures (115, 77 and 32° F. respectively) must be expressed 
on different scales, and are therefore not comparable. It is difficult and in many- 
cases impossible to interpret the extent of the physical change from the range in 
readings, upon subjecting a bituminous substance to variations in temperature. 
In addition, the scope of the penetrometer is limited, as it will not answer for either 
semi-liquid or hard bituminous materials. These objections are overcome in the 
consistometer. 

Test 9c. Consistometer. This instrument is constructed according to scientific 
principles, and may accurately be duplicated at any time. It registers the degrees 
hardness on a scale ranging from to 100, and may be used for determining the 
hardness of substances as soft as vaseline (which will test 0.3 at 77° F.) to sub- 
stances as hard as gilsonite (testing in the neighborhood of 100 at 77° F.). In 
all cases, the hardness or consistency is expressed as the cube root of the number 
of grams which must be appHed to a circular flat surface 1 sq.cm. (100 sq.mm.) 
in area, to cause it to displace the substance at a speed of 1 cm. per minute. 
Readings for all bituminous substances and at all temperatures (whether 115, 77 
or 32° F.) are expressed on a single scale. The harder the substance, the greater 
will be its hardness expressed numerically. 

Four mushroom-shaped plungers are used, each having a round flat head with 
a reduced shank, so the perimeter of the penetrating surface forms a " knife " edge. 
This entirely eliminates the fractional adhesion of the bituminous substance to the 
sides of the plungers. The flat heads of the plungers are made in the following 
dimensions: 



Plunger 


Diameter in mm. 


Area in sq.mm. 


No. 1 


1.13 

3.57 

11.28 

35.67 


1 

10 

100 

1000 


No. 10 


No. 100 


No. 1000 





The method of testing consists in forcing one of the plungers into the substance 
at a uniform speed of 1 cm. per minute. The force is automatically registered in 
grams or kilograms. For any plastic substance, the number of grams required to 
effect this displacement is directly proportional to the volume displaced. The vol- 
umes displaced per minute by the respective plungers are 0.1, 0.10, 1.00 and 10.0 c.c. 
respectively. The relation between the plungers is therefore in the direct propor- 
tion of 1:10:100:1000. 

For the sake of uniformity, all readings are expressed in terms of the number of 
grams applied to plunger No. 100 (1 sq.cm.). In other words, the readings obtained 
with plunger No. 1000 are divided by 10, those obtained with plunger No. 10 are 
multiplied by 10, and those obtained with plunger No. 1 are multiplied by 100. 
The hardness or consistency is equal to the cube root of this number of grams. 

Two interchangeable springs are supplied, one registering in grams on a scale 
ranging to 1000 g., in 10 g. divisions, and the other for reading in kilograms on a 
scale ranging from to 10 kgs., in 0.1 kg. divisions. In using plungers No. 1 
and No. 10, the kilogram spring only should be employed. In using plunger No. 
100 either the gram or the kilogram spring may be employed, depending upon the 



PHYSICAL CHARACTERISTICS 



499 



hardness of the material. In using plunger No. 1033, the gram spring only should 
be employed. The relations are expressed in the following table: 



Plunger. 


Spring. 


Actual 
Reading. 


Converted 
to grams per 100 
sq.mm. Plunger. 


Cube Root grams 

Applied 100 
sq.mm. Plunger. 


1000 sq mm 


G. 
G. 

l Kg. 
Kg. 
Kg. 


/ From 10 g. 
I to 1000 g. 

/ From 100 g. 
I to 1000 g. 

/ From 1 . kgs. 
\ to 10.0 kgs. 

/ From 1.0 kg. 
I to 10.0 kgs. 

/ From 1.0 kg. 
I to 10.0 kgs. 


1 
100 

100 
1,000 

1,000 
10,000 

10,000 
100,000 

100,000 
1,000,000 


1.00 




4.64 

4.64 
10.00 


10 aq.mm. . ._ 

1 8Q mm 


10.0 
21.5 

21.5 
46.4 

46.4 




100.0 



Table XXXVI shows the relation between the con- 
sistometer readings and degrees hardness, bearing in mind 
that in every case the hardness is designated as the cube 
root of the number of grams applied to the No. 100 plunger 
(area 100 sq.mm.), to cause it to displace the substance 
at a speed of 1 cm. per minute. 

The cohsistometer is illustrated in Fig. 165. It is first 
levelled by the four screws A. The spring B is then 
attached, selecting the gram spring for soft substances, 
or the kilogram spring for hard substances. The steel 
shaft C is inserted and screwed firmly into place. The 
plunger D should then be screwed into the lower end of 
the shaft. Plunger No. 1 is used for hard and brittle 
substances, plunger No. 10 for moderately hard sohd 
substances, plunger No. 100 for moderately soft semi- 
sohd substances, and plunger No. 1000 for semi-hquid 

substances. 

The scale E is graduated in grams on one side, and 

kilograms on the other, and is reversible. It should be 

attached so that the graduations will correspond with 

the spring used, and adjusted so the indicator F will rest 

at the division. The maximum indicator G is also 

brought to the division using the small instrument H. 
The bituminous substance is melted at the lowest 

possible temperature and poured into a small receptacle 

as described for the needle penetration method. The tin 

box J containing the bituminous substance is then sup- 
ported underneath the machine in a vessel of water (not 

shown) maintained at the temperature at which the test 

is to be performed. The pressure is applied to the plunger 

by turning the hand-wheel 0, and the speed of displacement Fig. 165. — Consistometer. 




500 



ASPHALTS AND ALLIED SUBSTANCES 



TABLE XXXVI 
FOR CONVERTING CONSISTOMETER READINGS INTO POINTS HARDNESS. 

Pltjngek No. 1000 (1000 sq. mm.) — Gram Spring. 



Grams 
Applied 





10 


20 


30 


40 


50 


60 


70 


80 


90 





0.00 


1.00 


1.26 


1.44 


1.59 


1.71 


1.82 


1.91 


2.00 


2.08 


100 


2.15 


2.22 


2.29 


2.35 


2.41 


2.47 


2.52 


2.57 


2.62 


2.67 


200 


2.71 


2.76 


2.80 


2.84 


2.88 


2 92 


2.96 


3.00 


3.04 


3.07 


300 


3.11 


3.14 


3.17 


3.21 


3.24 


3.27 


3.30 


3.33 


3.36 


3.39 


40C 


3.42 


3.45 


3.48 


3.50 


3.53 


3.56 


3.58 


3.61 


3.63 


3.66 


500 


3.G8 


3.71 


3.73 


3.76 


3.78 


3.80 


3.83 


3.85 


3.87 


3.89 


600 


3.91 


3.94 


3.96 


3.98 


4.00 


4.02 


4.04 


4.06 


4.08 


4.10 


700 


4.12 


4.14 


4.16 


4.18 


4.20 


4.22 


4.24 


4.25 


4.27 


4.29 


800 


4.31 


4.33 


4.34 


4.36 


4.38 


4.40 


4.41 


4.43 


4.45 


4.46 


900 


4.48 


4.50 


4.51 


4.53 


4.55 


4.56 


4.58 


4.59 


4.61 


4.63 









Plunger 


No. 100 


(100 SQ. 


MM.) Kl 


Lo Spring 






100 


4.64 


4.79 


4.93 


5.07 


5.19. 


5.31 


5.43 


5.54 


5.65 


5.75 


200 


5.85 


5.94 


6.04 


6.13 


6.21 


6.30 


6.38 


6.46 


6.54 


6.62 


300 


6.69 


6.77 


6.84 


6.91 


6.98 


7.05 


7.11 


7.18 


7.24 


7.31 


400 


7.37 


7.43 


7.49 


7.55 


7.61 


7.66 


7.72 


7.775 


7.83 


7.88 


500 


7.94 


7.99 


8.04 


8.09 


8.14 


8.19 


8.24 


8.29 


8.34 


8.39 


600 


8.43 


8.48 


8.53 


8.57 


8.62 


8.66 


8.71 


8.75 


8.79 


8.84 


700 


8.88 


8.92 


8.96 


,9.00 


9.045 


9.09 


9.13 


9.17 


9.21 


9.24 


800 


9.28 


9.32 


9.36 


9.40 


9.44 


9.47 


9.51 


9.55 


9.58 


9.62 


900 


9.65 


9.69 


9.73 


9.76 


9.80 


9.83 


9.86 


9.90 


9.93 


9.97 









Plunger 


No. 100 


(100 SQ. 


MM.) — Kilo Spring 






Kilos 
Applied 


0.0 


0.1 


0.2 


0.3 


0.4 


0.5 


0.6 


0.7 


0.8 


0.9 


1.0 


10.0 


10.3 


10.6 


10.9 


11.2 


11.4 


11.7 


11.9 


12.2 


12.4 


2.0 


12.6 


12.8 


13.0 


13.2 


13.4 


13.6 


13.75 


13.9 


14.1 


14.3 


3.0 


14.4 


14.6 


14.7 


14.9 


15.0 


15.2 


15.3 


15.5 


15.6 


15.7 


4.0 


15.9 


16.0 


16.1 


16.3 


16.4 


16.5 


16.6 


16.75 


16.9 


17.0 


5.0 


17.1 


17.2 


17.3 


17.4 


17.5 


17.65 


17.8 


17.9 


18.0 


18.1 


6.0 


18.2 


18.3 


18.4 


18.5 


18.6 


18.7 


18.8 


18.85 


18.95 


19.0 


7.0 


19.1 


19.2 


19.3 


19.4 


19.5 


19.6 


19.7 


19.75 


19.8 


19.9 


8.0 


20.0 


20.1 


20.2 


20.25 


20.3 


20.4 


20.5 


20.6 


20.65 


20.7 


9.0 


20.8 


20.9 


20.95 


21.0 


21.1 


21.2 


21.25 


21.3 


21.4 


21.5 









Plunger No. 10 


(10 SQ. MM.) — Kilo Spring 








1.0 


21.5 


22.2 


22.9 


23.5 


24.1 


24.7 


25.2 


25.7 


26.2 


26.7 


2.0 


27.1 


27.6 


28.0 


28.4 


28.8 


29.2 


29.6 


30.0 


30.4 


30.7 


3.0 


31.1 


31.4 


31.7 


32.1 


32.4 


32.7 


33.0 


33.3 


33.6 


33.9 


4.0 


34.2 


34.5 


34.8 


35.0 


35.3 


35.6 


35.8 


36.1 


36.3 


36.6 


5.0 


36.8 


37.1 


37.3 


37.6 


37.8 


38.0 


38.3 


38.5 


38.7 


38.9 


6.0 


39.1 


39.4 


39.6 


39.8 


40.0 


40.2 


40.4 


40.6 


40.8 


41.0 


7.0 


41.2 


41.4 


41.6 


41.8 


42.0 


42.2 


42.4 


42.5 


42.7 


42.9 


8.0. 


43.1 


43.3 


43.4 


43.6 


43.8 


44.0 


44.1 


44.3 


44.5 


44.6 


9.0 


44.8 


45.0 


45.1 


45.3 


45.5 


45.6 


45.8 


45.9 


46.1 


46.3 









Plunger No. 1 


(1 so. MM.) — Kilo 


Spring 






i 


1.0 


46.4 


47.9 


49.3 


50.7 


51.9 


53.1 


54.3 


55.4 


56.5 


57.5 


2.0 


58.5 


59.4 


60.4 


61.3 


62.1 


63.0 


63.8 


64.6 


65.4 


66.2 


3.0 


66.9 


67.7 


68.4 


69.1 


69.8 


70.5 


71.1 


71.8 


72.4 


73.1 


4.0 


73.7 


74.3 


74.9 


75.5 


76.1 


76.6 


77.2 


77.75 


78.3 


78.8 


5.0 


79.4 


79.9 


80.4 


80.9 


81.4 


81.9 


82.4 


82.9 


83.4 


83.9 


6.0 


84.3 


84.8 


85.3 


85.7 


86.2 


86.6 


87.1 


87.5 


87.9 


88.4 


7.0 


88.8 


89.2 


89.6 


90.0 


90.45 


90.9 


91.3 


91.7 


92.1 


92.4 


8.0 


92.8 


93.2 


93.6 


94.0 


94.4 


94.7 


95.1 


95.5 


95.8 


96.2 


9.0 


96.5 


96.9 


97.3 


97.6 


98.0 


98.3 


98.6 


99.0 


99.3 


99.7 


10.0 


100.0 


100.3 


100.7 


101.0 


101.3 


101.6 


102.0 


102.3 


102.6 


102.9 



PHYSICAL CHARACTERISTICS 501 

controlled by following the pointer K, on the dial L, which should be caused to 
revolve at the same speed as the second hand of a chronometer M, conveniently 
suspended alongside. The numbers on the dial L correspond with those of the 
second hand on the chronometer. One revolution of the pointer K indicates that the 
plunger has moved downward exactly one centimeter. 

At the termination of 60 seconds, after the pointer on the dial has made one 
revolution, the pressure on the plunger is reheved. The reading of the maximum 
indicator G on the scale E is then noted, and the corresponding degree of hardness 
ascertained by referring to the table. 

When the plunger commences to displace the substance at the specified speed 
of 1 cm. per minute, a maxim.um reading is obtained which should remain constant 
throughout the entire displacement. The consistometer is simple to operate, gives 
closely concordant results, expresses the readings obtamed at all temperatures on 
one scale and has a sufiiciently great range to ix^elude all bituminous substances 
ordinarily encountered.^ 

Test 9d. Susceptibility Factor. This factor is a numerical expression representing 
the susceptibility of a bituminous substance to temperature changes. The more 
susceptible the material the higher will be its " susceptibility factor." It is cal- 
culated from the consistometer hardness and the K. and S. fusing-point (Test 15a) 
in the following manner: 

., .,. .^ (Hd at 32° F.)-(Hd at 115° F.) _^ 

Susceptibility Factor = -—^ r——;z , ^ ,, , — rXlOO 

Fusing-pomt, K. and S. Method 

This factor is useful as a means of identification; for predetermining the adapta- 
bility of the substance for certain usages; gauging its uniformity of supply; and 
for purposes of factor control. This factor bears no relation to the hardness or 
fusing-point, and is substantially constant for bituminous substances derived from 
the same source or produced by the same general process. In the case of blown 
petroleum asphalts, it furnishes an indication of the extent to which the substance 
has been blown; the further the process having been continued, the smaller the 
factor expressed numerically. With residual asphalts derived from any one crude, 
the susceptibility factor will remain constant, regardless of the extent to which the 
distillation has progressed. 

By means of the susceptibility factor, bituminous materials may be roughly 
divided into the follovv^ing groups, viz.: 

Susceptibility Factor under 40: Includes blown petroleum asphalts, fatty-acid 
pitches and fluxed asphaltites (having a factor between 8 and 40); also wurtzihte 
asphalts (having a factor between 30 and 40). 

Susceptibility Factor between 40 and 63: Includes residual asphalts. 

Susceptibility Factor over 60: Includes mineral waxes, pitches derived from tars, 
and asphaltites (of which the susceptibility factor varies from 75 to over. 100). 

Native asphalts have been excluded from the foregoing groups, since their sus- 
ceptibiUty factors vary widely, ranging from 15 to greater than 100. The author 
has never examined a bituminous material having a susceptibility factor lower than 8.' 

**' Improved Instruments for the Physical Testing of Bituminous Materials," by Herbert Abra- 
ham, Proc. Am. Soc. Testing Materials, 9, 568. 1909; 11, 676, 1911; U. S. Pat. 989,471 of Apr. 
11, 1911 to Herbert Abraham. 

'"Improved Instruments for the Physical Testing of Bituminous Materials," by Herbert 
Abraham, Proc. Am. Soc. Testing Materials, 11, 683, 1911. 



502 ASPHALTS AND ALLIED SUBSTANCES 

Test 10. Ductility. This represents the capacity of the bituminous 
material for elongating or stretching. The test is of value for identify- 
ing the bituminous substance, for indicating its adaptability in con- 
nection with certain usages, for gauging its uniformity of supply, and 
for purposes of factory control. The ductility test often enables us to 
differentiate between blown petroleum asphalts and native or residual 
asphalts. Most pitches derived from tars are extremely ductile, but 
fatty-acid pitches are variable in this respect. The ductility test is 
useful for predetermining the adaptability of bituminous materials for 
paving purposes, for adhesive compounds to be used in connection with 
waterproofing or built-up roofing work, and for manufacturing surface 
coatings of prepared roofings. Wherever the bituminous material is 
subjected to extensive changes in temperature or vibration, it is im- 
portant that it should have high ductility within the particular tem- 
perature range to which it will be subjected. With every bituminous 
substance there exists a certain temperature, usually within 10 to 30° F. 
of its fusing-point (K. and S. method), at which the ductility attains 
a maximum. A ductility curve constructed for any bituminous sub- 
stance over a range of temperature assumes the same form as the 
probability curve in higher mathematics. It is desirable that the 
maximum ductility should coincide as closely as possible with the 
average temperature to which the material is to be subjected. 

There are two methods in use, depending upon the construction of 
the moulds, namely one devised by A. W. Dow, and one proposed by 
the author. 

Test 10a. Dow Ductility Test. The Dow mould is constructed of four brass 
parts as illustrated in Fig. 166, and of the following dimensions: external length 

9 cm., internal length 7.5 cm., distance between the 
ends of clips 3.0 cm., extreme internal width of mould 
3.0 cm., internal width at mouth of clips 2.0 cm., 
internal cross-section half-way between clips 1.0 cm., 
and thickness of briquette 1.0 cm.i The two centre 
pieces should be well amalgamated to prevent the 
Courtesy of Humboldt Mfg. Co. bituminous material from adhering, and the mould 
Fig. 166. — Dow Ductihty Mould, assembled on an amalgamated brass plate. The 

bituminous material is melted at the lowest possible 
temperature, poured in a steady stream into the centre of the mould, and a slight excess 
added to allow for shrinkage on coohng. The mould is cooled in air and levelled off with a 
hot spatula. The two centre pieces are then removed, leaving the briquette of bitumi- 

i"The Testirg of Bitumens for Paving Purposes," by A. W. Dow, Proc. Am. Soc. Testing 
Materials, 3, 352, 1903; "Report of the Commissioners of the Dist. of Columbia, for the year 
ending June 30, 1904," p. 42; "Methods for Testing Asphalt." by A. W. Dow, Chem. Eng., 1, 
330, 1905; "Tests of Asphalts for Paving Purposes," by A. W. Dow and F. P. Smith, Munic. 
Eng., 40, 437, 1911. 




PHYSICAL CHARACTERISTICS 



503 



nous material held at either end by the clips, and carefully transferred to a vessel 
of water maintained within 1 degree of the required temperature for at least 1, 
but not longer than 2 hours. The clips should then be pulled apart under water 
maintained within 1 degree of the required temperature, at a uniform rate of speed 
of 5 cm. per minute. The line of pull should be horizontal or nearly so, and the 
separation effected without appreciable vibration. Three tests should be averaged. ^ 




Courtesy of Howard & Morse. 

Fig. 167.— Smth Ductility Machine. 

It is customary to make this test at three temperatures, viz.: 115, 77 and 32° F. 
Various machines have been proposed for this purpose, including the one devised by 
Smith, illustrated in Fig. 167.^ 

An instrument with a dynamometer attachment adapted to use the Dow mould, 
measuring both the ductility and "cementi- 
tiousness " (tensile strength) has been de- 
scribed by Lester Kirschbraun.^ This device 
is essentially the same as that which had 
been previously described by the author in 
1910. (See test 106). 

Test 10b. Author's Ductility Test. An 
improved mould designed by the author, 
is illustrated in Fig. 168 and shown in 
cross-section in Fig. 169. It consists of two 
cylindrical sections constructed of hardened 
steel, resting together on circular knife- Fig. 168. — Author's Ductility Mould. 

1" Report of Sub-Committee on Ductility Tests," Proc. Am. Snc. Testing Materials, Part I, 15, 
349, 1915. 

2 "Machine for Testing the Ductility of Bituminous Paving Cements," by F. P. Smith, Proc. 
Am. Soc. Testing Materials, 9, 594, 1909. 

3 "The Cementing Value of Bituminous Binders," by Lester Kirschbraun, J. Ind. Eng. Chem., 
6, 976, 1914;' U. S. Pat. 1,180,506 of Apr. 25. 1916. 




504 



ASPHALTS AND ALLIED SUBSTANCES 



edges and maintained in that posi ion by three- guide pins. It is filled by unscrew- 
ing the upper cap and pouring in the melted bituminous substance, which on 
cooling forms a prismoid, whose altitude is 2.5 cm., the end-are is 1.8 cm. in diam- 
eter, with a minimum cress-section at the centre of exactly 1.0 sq.cm. (1.28 cm. in 
diameter). The upper cap is screwed in place, the mould fastened in the tensom- 
eter and the two halves separated at the uniform speed of 5 cm. per minute. 
The elongation in cms. at the moment the material pans is a measure of its 
ductihty.^ 

This mould has a number of advantages over the Dow type, including its adapta- 
bihty to testing semi-liquid and semi-solid bituminous materials, no amalgamation 
is necessary, there is no danger of the material breaking in the mould upon being 




j ] 1 L^0.75kl i 1 1 






1 1 1 K U28 ^ 1 1 ! 






1 1 K— 1.80 -->i [ 1 
1 k 2.15 --->' 1 


NQTe, 


All dimensions 


k 2.50 n 




in centimeTer$ 


* /^S^^^^^xi 







;o: 



Fig. 169. — Cross-section Author's Mould. 



cooled to the proper temperature, the personal equation is eliminated in filling 
the mould with the assurance that the minimum cross-section will he exactly the 
proper cize, and only a small quantity of the material is required in making the test. 
The tensometer is illustrated in Fig. 170. The two sections of the mould ^-1 
and A-2 are clamped between the guides .B-1 and B-2, the lower section being fast- 
ened to the stationary cross-piece C by the pin D-1, and the upper section to the 
movable cross-head E by the pin D-2. The cross-head is attached to the chain F 
which passes over the sprocket-wheel G fastened to the dynamometer H, and then 
around a suitable winding mechanism 7. The specimen is drawn apart by turning 
the hand- wheel J which operates the endless chain K running on the sprocket 
wheels L-1 and L-2. The dynamometer is equipped with a trigger M to prevent 
recoil. The chain F also connects with a train of gears operating the brass pointer 
N pressing against the dial which is formed of vulcanite or some other insulating 

1" Improved Instruments for the Physical Testing of Bituminous Materials," by Herbert Abra- 
ham, Proc. Am. Soc. Testing Materials, 10, 444, 1910; 11, 679, 1911. 



PHYSICAL CHARACTERISTICS 



505 



material. 

contact. 



Its face 

As the 



is marked in one hundred divisions, each consisting of a metallic 
pointer brushes over these contacts it momentarily closes an 
electric circuit which operates the relay P, 
causing a " cHck." The relay is connected with 
the batteries Q and the switch R. One revolution 
of the pointer indicates that the halves of the 
mould have been separated a distance of exactly 
one meter, and a movement of the pointer over 
one division of the dial corresponds to a centi- 
meter rise in the section A-2. 

The guides B-1 and B-2 are pivoted at *S-1 
and S-2, which permits the glass reservoir T 
being slipped into place, whereupon they are 
locked into position by the bolt U. The reser- 
voir is filled with water maintained at the 
desired temperature by the heating coil Y in 
series with the incandescent lamps V. The bath 
may be agitated upon squeezing the bulb W, 
vi^hich forces air through the liquid. The valve 
X is for emptying the reservoir. The speed is 
controlled by a metronome Mith a bell attach- 
ment set to ring every 12 seconds, or 5 times 
per minute. The speed with which the cranlc 
is turned must be regulated so that the " clicks " 
of the relay are brought into unison with the 
rings of the metronom.e. 

The reservoir should be filled 
with a hquid having about the son e 
specific gravity as the bituir.inous 
material tested, so the thread of 
material will neither have a ten- 
dency to float nor sink while the 
moulds are being separated. The 
operator m.ust watch the specim.en 
as sections A and B separate", and 
he should cease turning the crank 
at the morrent the thread parts. 
The dynamometer indicates the 
tensile strength of the substance in 
kilograms (Test 11), and the dial 
its ductility in centimeters. The 
substance is usually tested at 115, 
77 and 32° F. 




Fig. 170.— Tensometer. 



Test 11. Tensile Strength 
by the Author's Method. This 
is recorded on the tensometer 
as described in Test 106, and is equal to the maximum reading in 
kilograms as the two halves of the mould separate. It is a measure 



506 ASPHALTS AND ALLIED SUBSTANCES 

of cohesiveness or cementitiousness and is of value in determin- 
ing the adaptability of a bituminous substance for certain definite 
purposes, especially for paving, manufacturing adhesive compounds 
for waterproofing and built-up roofing work, bituminous substances 
for electrical insulation, moulded articles, pipe joints, etc. The 
tensile strength is ordinarily tested at 115, 77 and 32° F. For each 
bituminous substance, there is a critical temperature at which the ten- 
sile strength tests a maximum, and this is generally coincident with the 
temperature at which the ductihty approaches 0. This phenomenon 
may be explained by the disappearance of plasticity and associated 
cohesiveness at temperatures when the substance becomes transformed 
into a brittle solid. The tensile strength curve is also similar in form 
to the probability curve in higher mathematics. There appears to be no 
definite relation between the hardness and tensile strength of bituminous 
substances. With residual asphalts manufactured from the same crude, 
the tensile strength is reduced after the distillation progresses beyond 
the hard and brittle stage. Excessive blowing produces the same 
results, but to a lesser degree. 

Test 12. Adhesiveness Test. This test serves as a measure of the 
adhesiveness of the bituminous material, and it is of primary impor- 
tance in ascertaining its adaptability for certain definite usages, as, for 
example, in road building, preparing compounds for water-proofing 
and built-up roofing work, cements, etc. It represents the capacity of 
the substance to adhere to solid objects with which it may be brought 
in contact, and differs entirely from the cohesiveness or tensile strength 
referred to in Test 11. Various instruments have been proposed for 
this purpose including those devised by Fulweiler,^ Osborne, Kirschbraun 
and others. 

Test 12a. Osborne Adhesive Test. This is designed especially for measuring 
the adhesion of semi-Hquid to semi-soHd road oils suitable for the construction 
of carpet or seal coats (p. 367). 

The apparatus is illustrated in Fig 171 and is composed of two concentric 
cylinders. The stationary inner cyHnder is hollow and measures exactly 1.995 in. 
in diameter. It is maintained at 77° F., by a stream of water circulating through 
it, entering and leaving by the horizontal tubes shown to the right, one bearing a 
thermometer to register its temperature. The movable outer cylinder or collar, 
2.000 in. in diameter and 2 in. wide is caused to revolve on the inner cyhnder 
with a uniform layer of the bituminous material to be tested in between, by being 
wound with a cord attached to a 3 kg. weight. The thin film of bituminous mate- 
rial between the cylinders offers a resistance of this turning, and the adhesive 

i"A New Machine for Testing Pitch," by T. Y. Olsen, Proc. Am. Soc. Testing Materials, 10, 
592, 1910; "Impact Testing Machine for Pitch," by W, H. Fulweiler, Am. Assoc. Adv. Set., 
Wash., D. C, 1911; "Good Roads," 3, 81, 1912. 



PHYSICAL CHARACTERISTICS 



507 



value is measured by recording the length of time required for three complete 
revolutions of the collar. ^ Table XXXVII includes tests reported by the designer 
of the machine, the float test having been ascertained at 90° F. (Test 8d), and the 
viscosity by the Engler viscosimeter at 212° F. (Test 8a). 





Fig. 



Courtesy of C. B. Osborne. 

171. — Osborne Adhesive Tester. 



Courtesy of E. H. Sargent Co. 

Fig. 172. — Kirschbraun Adhesive Tester. 



Test 12b. Kirschbraun Adhesive Test. This is designed for testing semi-sohd 
to solid bituminous materials. The instrument is constructed as illustrated in Fig. 
172, consisting of a dynamometer with a maximum-reading indicator having a ball 
attached to its lower end. A platform with side clips for holding the container 
of the bituminous material is attached to a threaded bar, geared to a crank for 
raising or lowering the sample. The container is provided with side flanges by 
which it is held on the platform. The bituminous material is poured into the cup 
so as to enclose the ball, and when cooled to the desired temperature, the platform 
is lowered at a uniform speed until the ball withdraws from the specimen under test. 
The adhesion is recorded by the dynamometer. 

1 Private communication from Clarence B. Osborne of the California Highway Commission, 
Sacramento, Cal. 



508 



ASPHALTS AND ALLIED SUBSTANCES 



TABLE XXXVII 



Sp.gr. 
at 77° F. 

Test 7). 


Solubil- 
ity in 

Carbon 
Disul- 
phide 
(Test 
21a) 


Flash- 
point °F. 

(Test 17) 


Burning 
Point °F. 
(Test 18) 


Float 
Test at 
90° F. 

(Test Sd) 


Viscosity 
Test at 
212° F. 

(Test 8a) 


Osborne 

Adhesive 

Test at 

77° F. 

(Test 

12a) 


Less in 

5 Hours 

325° F. 

(Test 

16) 


Float 
Test at 
90° F. 
a'ter 5 
Hours 

at 
325° F. 


% 
Asphalt 
(of 80 
Penetra- 
tion at 
77° F.) 
at 400° 
F. 


Hours 

Heated 

at 400° 

F. 


0.998 


99.74 


339 


460 


390 


1312 


690 


2.68 


1113 


92.0 


9.0 


0.935 


99.78 


216 


290 


72 


427 


26 


15.37 


8055 


80.0 


3.5 


1.001 


99.83 


277 


415 


186 


584 


281 


3.48 


706 


89.1 


8.5 


0.979 


99.91 


325 


450 


93 


334 


40 


3.24 


149 


86.2 


25.0 


0.971 


99.90 


280 


355 


29 


143 


5.5 


8.01 


86 


75.6 


32.0 


0.932 


99.93 


360 


525 


187 


591 


208 


0.90 


234 


92.5 


30.0 


0.973 


99.86 






29 


129 


6.2 


12.58 


132 


70.2 


8.0 


0.997 


99.90 


330 


420 


143 


438 


125 


1.71 


225 


87.7 


14.0 


0.996 


99.46 






651 


1573 


1,006 


0.17 


1019 


95.5 


14.0 


0.993 


99.94 






146 
132 


481 
413 


119 
80 


4.28 


315 


86.0 


10.0 


0.995 


99.85 






280 


946 


430 


3.09 


837 


91.7 


10.0 


0.990 


99.78 






135 


443 


73 


2.43 


217 


81.3 


14.0 


0.S92 


99.78 


350 


426 


130 


430 


99 


4.43 


292 


84.2 


14.0 


0.993 


99.77 


340 


428 


141 


436 


110 


5.22 


368 


84.7 


14.0 


0.998 


99.77 






181 


566 


197 


1.94 


284 


90.2 


19.0 


0.986 


99.96 


358 


480 


132 


474 


141 


2.31 


214 


89.0 


20.0 


0.984 


99.88 


444 


528 


230 


724 


409 


0.27 


289 


93.0 


26.0 


0.996 


93.95 


345 


418 


133 


414 


112 


5.81 


379 


85.0 


10.0 


0.998 


99.82 


428 


518 


420 


1238 


450 


0.36 


538 


94.0 


4.5 


0.991 


99.83 


318 


410 


136 


419 


104 


4.19 


277 


85.0 


13.0 


1.027 


99.59 


304 


420 


1702 


4090 


3,960 


3.88 


115* 


92.9 


3.0 


0.991 


99.85 


315 


405 


201 


630 


315 


4.2 


591 


88.0 


8.0 


0.984 


99.92 


320 


522 


212 


727 


313 


0.6 


302 


92.3 


20.0 


0.992 


99.91 


280 


474 


147 


425 


90 


2.3 


259 


88.5 


12.0 


0.997 


99.90 


310 


418 


151 


552 


161 


5.9 


496 


85.5 


7.0 


1.007 


99 . 69 


250 


400 


575 


2108 


590 


6.5 




89.6 


3.0 


0.997 


99.95 


335 


428 


249 


882 


218 


5.2 


720 


88.3 


6.0 


0.992 


99.73 


235 


365 


316 


1370 




9.0 


136* 


87.0 


3.0 


0.996 


99.96 


360 


440 


454 


873 


710 


1.4 


839 


90.6 


7.0 


1.012 


99.84 


385 


494 


8490 


8342 


20,880 


1.5 


76* 


97.2 


1.5 


0.994 


99.77 


385 


470 


308 


709 


670 


2.2 


570 


88.2 


15.0 


0.984 


99.93 


315 


525 


208 


666 


310 


0.5 


226 


92.2 


28.0 


0.986 


99.65 


420 


530 


849 


900 


928 


0.6 


887 


95.0 


13.0 


1.017 


99.84 


380 


470 


147* 


9213 


10,710 


1.7 


85* 


97.0 


2.5 


0.991 


99.90 


405 


525 


429 


925 


520 


1.0 




95.2 


20.0 


0.998 


99.94 






210 




260 


2.8 




88.0 


11.5 


0.997 


99.86 






320 




487 






92.0 


7.5 


1.006 


99.67 


380 


480 


142* 


8015 


15,600 






97.8 


1.5 


0.989 


99.93 


315 


398 


137 


445 


164 






84.2 


17.0 


1.021 


99.80 


375 


485 


140* 


8220 


22,500 







98.1 


1.5 


0.995 


99.78 






150 




150 








86:9 


13.0 



* Penetration at 77"* F. 



CHAPTER XXIX 
HEAT TESTS 

Test 13. Odor on Heating. This test serves as a valuable guide 
for identifying bituminous materials. The following substances in partic- 
ular may be recognized when present in the pure state or in admixture 
with other substances, by their characteristic odor evolved upon heating. 

Oil-gas-tar Pitch, Water-gas-tar Pitch and Coal-tar Pitches: Odor, acrid, 
sharp and penetrating. 

Wood-tar Pitches: Odor somewhat similar to that of coal-tar pitches, 
also characteristic but less sharp and intense. 

Fatty-acid Pitches: Odor sweetish and bland, also characteristic. 

Asphalts (including native and pyrogenous asphalts): Odor oily and 
some cases slightly sulphurous. 

Gilsonite: Odor characteristic but cannot very well be described in 
words. 

Test 14. Subjection to Heat. Certain bituminous substances be- 
have in a characteristic manner upon subjecting them to the influence 
of heat, which also assists in their identification. 

Test 14a. Behavior on Melting. Some bituminous materials pass rapidly from 
the solid to the liquid state on heating, as for example the mineral waxes, most of 
the native asphalts, residual asphalts, sludge asphalts, peat-tar pitch, lignite-tar 
pitch, oil-gas-tar pitch, water-gas-tar pitch, and the coal-tar pitches. On the other 
hand, many bituminous materials, especially those of a low susceptibility factor 
(Test 9d) melt sluggishly, and pass through an intermediate " pasty " stage; as 
for example blown petroleum asphalt, wurtzilite asphalt, asphaltites and the saponi- 
fiable fatty-acid pitches. The same is manifested by any bituminous materials 
containing large proportion of mineral matter, also those which have been sul- 
phurized. Capp and Hull have devised a method for depicting this graphically. ^ 

Test 14b. Behavior on Heating in Flame. This test is especially useful for 
hard and solid bituminous materials, and constitutes a rapid method for distin- 
guishing between those which are fusible and infusible. Fusible bituminous sub- 
stances, including the mineral waxes, asphalts, asphaltites and pitches will behave 
in one of the following ways: they may simply soften and flow, as proves to be 
the case with mineral waxes, asphalts, gilsonite, glance pitch and the true pitches. 
If moisture is present, these substances will decrepitate. Grahamite acts in a 
characteristic manner, those varieties showing a hackly fracture, soften, split and 

i"A Method for Studying the Effe^^ts of Temperature upon the Physical Con^lition of As- 
phalts, Waxes, etc.," by J. A. Capp and F. A. Hull Proc. Am. Soc. Testing Materials, 17, 627, 1917. 

509 



510 ASPHALTS AND ALLIED SUBSTANCES 

burn in the flame, whereas those showing a conchoidal fracture decrepitate vio- 
lently even when no moisture is present. 

The asphaltic pyrobitumens also behave in characteristic manners. They will 
not fuse in the flame, but when dry, act as follows: elaterite and wurtzilite burn 
quietly, albertite intumesces, whereas impsonite decrepitates. 

Test 15. Fusing C Melting ") Point.^ This constitutes one of the 
most valuable all-around tests. It is used for purposes of identifica- 
tion, especially with materials fusing at a high temperature, such as 
the asphaltites, and is particularly useful in this connection upon tak- 
ing into consideration the specific gravity and hardness. It is also 
used for ascertaining the adaptability of a bituminous material for 
certain definite usages, including its resistance to the sun or artificial 
heat. The fusing test serves to gauge the uniformity of supply, and 
on account of its rapidity and accuracy, is used extensively for pur- 
poses of factory control. Several methods have been proposed for this 
purpose, viz.: 

Test 15a. Kramer-Sarnow Method. This method is rapid, accurate, and adapts 
itself either to soft or hard bituminous materials, from residual oils up to gra- 
hamite. Its range is greater than that of any other fusing-point method. 

It was first proposed by G. Kramer and C. Sarnow.^ Various modifications have 
been suggested from time to time.' The author has made a careful study of this 
method, and recommends the following procedure:* 

Substances Fusing helow the Boiling-point of Water. This method consists in 
heating a plug of the bituminous substance 5 mm. long, in an open glass tube, 
6-7 mm. internal diameter, and about 8 cm. long, the plug supporting 5 g. mer- 
cury, and the tube being immersed in a vessel of water, the level of which reaches 
approximately the centre of the mercury column. In making the test, a thermom- 
eter is suspended in the Hquid, so its bulb will be at the same level as the plug 
of bituminous material. The thermometer is supported in a separate glass tube of 
the same thickness and diameter as the other tube, but differing therefrom in 
having its lower end sealed, and containing sufficient mercury to surround the bulb. 
The water is heated at a uniform rate of 4'' F. per minute, and the temperature 
at which the mercury drops through the plug of bituminous material recorded as 
its fusing temperature. The tube containing the bituminous substance may have a 
mark etched 5 mm. from the end, as a convenient guide for the quantity of bitu- 

1 The term " fusing-point " has been used throughout the text in place of the phrase " melting- 
point," since the former is more expressive of the behavior of fusible bituminous substances under 
the influence of heat. They pass gradually from the solid to the liquid condition, the transition 
taking place slowly, owing to the heterogeneous character of the substances present. The phrase 
" melting-point " is more appropriately applied to chemical substances having a definite compcsi- 
tion, which melt sharply, and within a narrow temperature range. 

^Chem. Ind., 26, 55, 1903. 

2 B. M. Margosches, Chem. Rev. Fett-Harz-Ind., 11, 277, 1904; M. Wendriner, Z. angew. Chem., 
18, 622, 1905; E. Graefe, Chem. Zeit., 30, 298, 1906; Bauert, Chem. Zeit., 29, 382, 1905; OfTer- 
mann. Petroleum, 6, 2117, 1910; L. Barta, Petroleum, 7, 158, 1911; V. Abeles, Chem. Zeit., 38, 
249, 1914. 

4 "Improved Instruments for the Physical Testing of Bituminous Materials," by Herbert Abra- 
ham, Proc. Am. Soc. Testing Materials, 9, 575, 1909; 11, 673, 1911. 



HEAT TESTS 



511 



minous material to be introduced. The plug of bituminous material may be intro- 
duced into the tube by inverting it and inserting from its lower end a well-fitting 
cork or wooden plug fastened to a stiff wire. The mercury is poured on same, 
and the plug raised or lowered until the meniscus of the mercury coincides with 
the mark etched on the tube. The bituminous material is then melted at a tem- 
perature shghtly above its fusing-point and poured on top of the mercury, to 
completely fill the tube, which should be warmed slightly. When cool, the bitu- 
minous material is levelled off even with the end of the tube, whereupon the tube 
is inverted and the plug withdrawn. This is illustrated in Fig. 173. 



Mark etched 

on Tube 
''5 gr. Mercury 
^'- Cork or Plug 



■Glass Tube 




Fig. 173.— Method of Filling K. 
& S. Fusing-Point Tubes. 



Fig. 174.— Heating Coil for K. & S. Fusing- 
Point Tester. 



The mercury is measured from a heavy- walled capillary tube of 1 mm. bore, 
terminating in a three-way cock, as illustrated at j, Fig. 175, and calibrated to hold 
exactly 5 g. mercury at room temperature. The short limb of the tube is con- 
nected with a movable reservoir containing mercury, the height of which is adjusted 
so the mercury in the capillary tube exactly reaches the graduation. 

The heating is conveniently effected by an electrical device described by the 
author,^ illustrated in Fig. 174, composed of a coil of resistance wire to be immersed 

»Proc. Am. Soc. Testing Materials, 9, 577. 1909. 



512 



ASPHALTS AND ALLIED SUBSTANCES 



in the liquid bath containing the fusing-point tubes, and connected with a rheostat, by 
means of which the temperature may be controlled to a nicety. Three slabs of slate 
or asbestos-cement, a, b and c, are fastened together with three small bronze bolts d-1, 
d-2 and d-3, also three large bolts, e-1, e-2 and e-3 enclosed in glass tubes / and g 
respectively, to prevent short circuiting. The coil h consists of 10 yd. of cotton- 
covered No. 30 ni chrome resistance wire wound in a single layer around the tubes, 
and connected with the bolts e-2 and e-3, which in turn terminate in binding-posts 
i and j. The coil after being assembled is treated with a high-grade insulating 





Fig. 175.— K. & S. Fusing-Point Tester. 



varnish and baked until hard. Ten holes are drilled in the slab a, three e, for the 
large bolts, six k for the fusing-point tubes and one I, for the thermometer tube. 
The coil as described offers a resistance of 75 ohms, and allows a passage of approxi- 
mately 1.5 amperes at a potential of 110 volts. It will raise the temperature of 
500 to 600 c.c. of water to the boiling-point in a few minutes, when the full current 
is applied. 

The apparatus is assembled as illustrated in Fig. 175. The heating coil A 
carrying the thermometer B and the fusing-point tubes C is counterbalanced by the 
weight D, so it may be raised or lowered into the beaker E holding 500-600 cc. 



HEAT TESTS '513 

of water. The heating coil is connected with a rheostat F and a switch G in parallel 
with an 8 c.p. incandescent lamp // behind the beaker to illuminate the fusing- 
point tubes, and a 32 c.p. lamp / to light up the interior of the apparatus; / 
represents the mercury measuring-device, and K a clock from which the hour hand 
has been removed, and the dial graduated in 240 divisions representing degrees 
Fahrenheit. The rise in temperature is synchronized with the minute hand of the 
clock and controlled by the rheostat to increase exactly 4° F. per minute. The initial 
temperature of the water should be at least 25° F. lower than the fusing-point of 
the material to be examined. Six tests may be run simultaneously. 

The heating coil is simple to construct, easy to operate, and insures a perfect 
temperature control. Owing to its skeleton construction, the heat is rapidly dis- 
sipated, and there is no danger of the coil burning out, provided it is kept immersed 
in the water while the current is on. In the author's laboratory, v/here the coils 
are in daily use, they last from 2 to 3 years, and when burnt out, the wiring may be 
renewed in a few minutes' time. 

Substances Fusing above the Boiling-point of Water. In this case the heating is 
performed by a direct flame, as illustrated in Fig. 176, the water being replaced 
with castor oil which may be heated safely to about 600° F. This method may 
be used for determining the fusing-point of asphaltites including grahamite. A 
small quantity of the high fusing-point bituminous material is powdered and com- 
pressed in the lower end of the fusing-point tube, whereupon it is carefully heated 
above the flame of a burner, until the plug of bituminous material softens and 
fuses to the tube, which is evidenced by the color changing from a dull to a glossy 
black. The tube is then stood upright against a block of wood, a snug-fitting glass 
rod inserted in the upper end, and pressed against the softened bituminous material 
to compact it into a soHd mass 7 to 9 mm. long. On cooling, the plug is then 
carefully scraped from the lower end of the tube until exactly 5 mm. remains, 
leaving an air space 2 to 4 mm. between the plug and the lower end of the tube. 
Care should be taken when suspending the fusing-point tube in the heating bath to 
allow the free space below the plug to remain filled with air, otherwise oil will 
come in contact with, and prematurely soften the bituminous material. The bath 
is heated at the uniform speed of 4° F. per minute.^ 

Test 15b. Ball and Ring Method. This method has been proposed by the 
American Society for Testing Materials. ^ The apparatus is illustrated in Fig. 177, 
and consis s of a "brass ring 15.875 mm. (fin.) in diameter, 6.35 mm. (j in.) 
deep, 2.38125 mm. (^ in.) wall; suspended 25.40 mm. (1 in.) above the bottom 
of beaker; a steel ball 9.525 mm. (| in.) in diameter, weighing between 3.45 and 
3.50 g.; a standardized thermometer; a glass beaker of approximately 600 c.c. 
capacity." 

" Carefully melt the sample and fill the ring with the material to be tested. 
Remove any excess. Place the ball in the centre of the ring and suspend in beaker 
containing approximately 400 c.c. water at a temperature at least 25° F. lower 
than the fusing-point of the sample to be tested. Arrange the thermometer bulb 
within ^ in. of the sample and at the same level. Apply heat uniformly over bot- 
tom of the beaker in quantity sufficient to raise the temperature exactly 9° F. per 

1 " Improved Instrurrents for the Physical Testing of Bituminous Materials," Proc. Am. Soc. 
Testing Materials, 11, 674, 1911. 

' 2 "Tentative Method for Determination of Softening Point of Bituminous Materials other than 
Tar Products," (Serial Designation; D 36-167), Proc. Am. Soc. Testing Materials, 17, Part I, 811, 1917. 



614 



ASPHALTS AND ALLIED SUBSTANCES 



minute. The rate of heating is very important. The softening point is the tern-, 
perature at which the specimen has dropped 1 in. Separate tests should average 
within 5° F. For temperatures above 200° F. glycerin should be used instead of 
water." 

The electrical heating coil described in Test 9a may be used to good advantage 
in the Ball and Ring method, but the length of nichrome wire should be reduced 
to 6 yd., to provide for the more rapid heating of the bath. 

Tests made by the author indicate that the Ball and Ring f using-points range 
15 to 25° F. higher than those obtained by the K. and S. method. This relation- 
ship holds true regardless of whether the fusing-point of the material is low or 
high. 



Fahrenheit 
Thermometer^" 



Fusing -Point- 
Tubes 



Liquid ^ 
Levei"^ 



Castor Oil 




6,7 mm$. 



\— Rubber Tubd 



t^.^Sgms. Mercury 
.,'5mms Bitumen 



-mm. Air 5paC9 



- Copper Gauze 



<- - "Magnesia -Asbestos 
Pipe Covering 



'— Tripod 




Fig. 176.— K. and S. Tester for High Fusing- 
Point Substances. 



From A. S. T. M. Standards. 

Fig. 177.— B. and R. Fusing- 
Point Tester. 



Test 15c. Cube Method. This method is restricted to testing tar-pitches.^ 
For Pitches Fusing below 170° F. The following method should be used, with an 
apparatus as illustrated in Fig. 178. The material is melted by the gentle appHca- 
tion of heat until it becomes sufficiently fluid to pour, care being taken that it 
suffers no appreciable loss by volatilization. It is then poured into the brass 
mould which has been amalgamated with mercury to prevent it sticking to the 
sides. After cooling, the cube of bituminous material is levelled, removed from the 
mould and placed on the hook of No. 12 copper wire as illustrated. It is then 
suspended in a 600-c.c. beaker containing 400 c.c. water, at least 40" F. lower 
than the fusing-point of the substance. The bottom of the cube should be 1 in. 
above the bottom of the beaker, and allowed to remain in it at least 5 minutes before 
the heat is applied. A sheet of paper weighed down on the bottom will prevent 

1 " Methods for Testing Coal Tar, and Refined Tars, Oils, and Pitches Derived Therefrom," 
by S. R. Church, J. Ind. Eng. Chem., 3, 230, 19ll; 5, 195, 1913. 



HEAT TESTS 



515 



the pitch adhering to the beaker when it drops off. Heat is apphed in such a man- 
ner that the temperature of the water is raised exactly 9° F. each minute. The 
temperature recorded by the thermometer at the instant the cube of pitch touches 
the bottom of the beaker is taken as its fusing-point. 

For Pitches Fusing above 170° F. The heating is performed in an air bath in the 
apparatus illustrated in Fig. 179. The cube should be suspended in line with 
the observation windows, and the thermometer bulb brought to the same level. The 
temperature is raised 9° F. per minute, and recorded by the thermometer when the 
cube drops 1 in. To make the results obtained by this method correspond approxi- 
mately with those obtained in water or oil, 12° F. should be added to the observed 
fusing-point. 

Investigations of the relationship between the Cube and the Ball and Ring 
methods ^ indicate that the results vary considerably, depending largely upon the 




Pitch MouldT- 
6as Tube 



Thermometer 



Copper O^en- 



Mica Windows on 
opposite sides - 



RemovableCoppei\;^'Z 
Tray 



Stand-- 




Fig. 178. — Cube Fusing-point Tester. 



Fig. 179.— Cube Tester for High Fusing- 
point Substances. 



nature of the products tested and their fusing-points. No exact factors can be given. 
The relation between the fusing-point by the Cube method with the results obtained 
by the Schutte consistency tester, the Engler viscosimeter and the float test have 
also been investigated.^ 

Test 15d. Flowing Temperature. This test has been proposed by Clifford 
Richardson^ and consists in heating a small cube measuring 1 cu.mm. on a micro- 
scopic cover-glass (No. 2-0) floated on the surface of mercury (or solder in the case 
of the very high fusing-point asphalts or asphaltites), in a deep 3 oz. seamless tin 
box (American Can Co.) 5.5 cm. in diameter and 3.5 cm. deep, filled to a distance 
of \ in. from the top, with mercury or solder. This is covered with an inverted 
funnel from which the stem has been cut, and a thermometer introduced through 
the orifice until the bulb is immersed. The heat is increased at the uniform speed 
of 9° F. per minute, and the temperature recorded when the specimen spreads 
out in a thin film over the cover-glass. This is designated as its " flowing-point." 

1" Methods for Determining the Melting-Point of Asphalts." by J. G. Miller and P. P. Sharp- 
ies, Proc. Am. Soc. Testing Materials, 14, Part II, 503, 1914; "Report of Sub-Committee on 
Softening Point," Proc. Am. Soc. Testing Materials, 15, Part I, 341, 1915. 

»" Relation Between the Melting-Point and the Viscosity of Refined Tars," by P. P. Sharpies, 
/. Ind. Eng. Chem., 6, 285, 1914. 

• "The Modern Asphalt Pavement," 2nd Edition, 538. 



516 ASPHALTS AND ALLIED SUBSTANCES 

Test 16. Volatile Matter. This test is used for identifying various 
bituminous materials. Thus in the case of asphalts, the volatilization 
test will often serve to identify soft native asphalts, which contain 
larger percentages of volatile matter than soft residual or blown petro- 
leum asphalts. Cut-back products also carry a large percentage of vola- 
tile constituents. The test may also be used to determine the adapta- 
bility of a bituminous substance for certain definite purposes, where it 
becomes necessary to heat it to high temperatures, as for example in 
the pav'ng industry or in manufacturing bituminized roofings and floor- 
ings. It likewise serves as a valuable adjunct for gauging the uni- 
formity of supply and for purposes of factory control. It also furnishes 
an indication of the weatherproof properties of the material. Other 
things being equal, bituminous substances showing the smallest per- 
centage of volatile matter will prove most weatherproof on exposure 
to the elements. It should be noted, however, that the volatility 
test alone must not be taken as the final criterion as to whether or 
not a bituminous substance is weatherproof, since other factors should 
also be taken into consideration (see p. 345). The volatility test may be 
regarded as an accelerated test, showing the loss of volatile constituents 
which will take place upon exposure to the weather in a relatively thin 
layer, for a long time. 

The following method has been proposed by the American Society 
for Testing Materials.^ 

" The amount lost by oils and asphaltic compounds when heated in an oven to 
325° F, (within 2° F.), shall be determined by heating 50 g. of the water-free 
substance (20 g. in the case of tars and pitches) in a flat-bottom dish, the inside 
dimensions of which are approximately 55 mm. in diameter by 35 mm. deep^ for 5 
hours. 

" The oven in which the substance is to be heated shall be brought to the 
prescribed temperature before the sample is introduced, and the temperature of the 
sample under test shall be regarded as that of a similar quantity of the same 
material immediately adjoining it, in which the bulb of a standardized thermometer 
is immersed. The oven may either be circular or rectangular in form, and the 
source of heat either gas or electricity. 

'* The samples under test shall rest in the same relative position in a single 
row upon a perforated circular shelf 24.8 cm. (9.75 in.) in diameter, as shown in 
Fig. 180, suspended by a vertical shaft midway in the oven, which is revolved by 
mechanical means at the rate of from 5 to 6 revolutions per njinute." 

The oven ordinarily employed for determining the volatile matter, illustrated 
in Fig. 181, is composed of a cylindrical vessel with a hinged cover, surrounded by 

1" Standard Test for Loss on Heating of Oil and A.sphaltic Compounds," (Serial Designation; 
D 6-16), of the Am. Soc. Testing Materials, 1916 Book of A. S. T. M. Standards, 533; "Tentative 
Specifications of Coal-tar Pitch " (Serial Designation, D 42-17 T), Proc. Am. Soc. Testing Materials, 17, 
Part T, 718, 1917. 

2 Three-oz. Gill style ointment box, deep pattern, manufactured by the American Can Co. 



HEAT TESTS 



517 



an insulated jacket, with an air space in between acting as a flue to carry off the 
hot gases generated by the ring-burner underneath. The oven is equipped with u 
revolving shelf to support the specimens under examination, and the temperature 
regulated by a mercury thermostat. 

An extension of this test recommended by the author, consists in heating the 
sample to 500° F. for 4 hours. This is advisable in examining relatively non- 
volatile asphaltic products, which would show but a fraction of a per cent loss by 
the foregoing method. 

It is customary to find the hardness of the residue after the determination of 
volatile matter by Method 96. 

Test 17. Flash-point. The flash point is used primarily for deter- 
mining the adaptability of bitmninous substances for certain definite 



!</ 



r^'nj^Lo 



/|,#^ ?^l*^f!: 5 •■--?■ flat, Sf'o 



ll-t 
'Mi^^'i ,-. 

k -^2" >^ 



■41- 



Section A-B. 




Thds. 



S Holes and Ribs 
Spaced Equally 



Top View 

From A. S. T. M. Standards 

Fig. 180.— Shelf for Volatility Oven. 

usages, and serves as a criterion of the fire hazard. It should be at least 
50° F. higher than the maximum temperature to which the bituminous 
substance will be subjected in the process of blending or utilization. 
This test is also sometimes used for gauging the uniformity of supply 
and for purposes of factory control. 

A number of flash-point testers have been proposed, of which the 
following are most generally used: 

Test 17a. Pensky-Martens Closed Tester. This apparatus has been adopted 
aa standard by the Government of the United States, and foreign governments for 
testing high flash-point bituminous materials. The instrument is illustrated in Fig. 182, 
and consists of an oil cup a, in a metal heating vessel 6, surrounded with a flanged 
top to prevent loss of heat by radiation. An orifice c permits the overflow of the 
oil into the jacket d between the oil cup and the heating vessel. It is likwise pro- 



518 



ASPHALTS AND ALLIED SUBSTANCES 



vided with a mechanical stirring device e, the thermometer /, the test flame g, 
burner ^, wire screen j, and spring k to work the sUde under the test flame. 

The approximate flash-point is ascertained by a preliminary test. The melted 
bituminous substance is poured into the Pensky-Martens tester, which should be 
perfectly level, taking care not to splash any on the sides of the cup, or to cause 
any froth on the surface. All bubbles should be pricked with a heated wire. The 
test flame is then regulated to correspond in size with the ivory bead on the cover 
(to burn 0.1 cu.ft. coal gas per hour). The burner i is lit, and the contents heated 
rapidly at first until the temperature reaches 50° F. below the expected flash-point, 
whereupon the rise in temperature should be controlled to increase exactly 5° F. 
per minute. At each degree the milled head k is turned and the flame g tilted 





Courtesy of Wm. Boekel & Co. 
Fig. 181.— Volatility Oven. 



Fig. 182. — Pensky-Martens Closed Flash- 
point Tester. 



into ths cup for exaculy one second. The test is continued until the flash-point occurs. 
Any slight iiickering or spreading of the flame is ignored. The end point is evi- 
denced by an unquestionable flash. The apparatus should be protected from 
draughts, and the sample stirred continuously during the test. If the thermometer 
is graduated to read for total immersion, the stem-correction should be applied. 
When this is done, it is suggested that " corr." be added to the reading, thus: 
" Flash 379° F. corr." 

A simplified form of Pensky-Martens tester for approximately determining the 
flash-point, consists of a glass beaker or metal cup having the same dimensions, 
namely 5.0 cm. in diameter, and 5.5 cm, in depth, filled to within 1.8 cm. of its 
upper rim with the material to be tested. This is supported on a sand bath and 



HEAT TESTS 



519 



the thermometer bulb immersed in the bituminous material without, however, 
touching the sides or bottom. The test flame is adjusted to a 3 mm. cross-section, 
and the test performed exactly as described for the Pensky-Martens tester.^ 

Test 17b. Cleveland Open Tester. This apparatus, illustrated in Fig. 183, 
consists of a brass cup a, holding 100 c.c, supported in an outer vessel b, with an 
air space between. The thermometer c is freely suspended in the bituminous 
material, so the bulb is totally covered. The cup is filled to j in. from the top, 
and the bituminous material heated at the rate of 10° F. per minute. As the 
flash-point is approached, the test-flame, which should be 5 mm. long, is slowly 
moved back and forth, so the top of the flame comes 2-3 mm. from the surface of 



r\ 





Fig. 183. — Cleveland Open Flash-point 
Tester. 



Fig. 184.— New York State Closed Flash- 
point Tester. 



the liquid, without, however, touching it or the sides of the container. This is 
repeated every 2° F. rise in temperature until the vapors flash. ^ 

Test 17c. New York State or Elliot Closed Tester. This is illustrated in Fig. 
184 and consists of a 300-cc. copper container C, heated in an oil bath D. The 
cup is provided with a glass cover, carrying the thermometer B and a hole for 
inserting the test-flame, the latter being 5 mm. long. The test is carried out by 
heating the contents with the burner A as in the foregoing, and the rise in tem- 
perature carefully regulated to 10° F. per minute.' 

»" Flash Point of Oils," by I. C. Allen and A. S. Crosafield, Tech. Paper No. 49, Petroleum 
Technology 10, Dept. of Interior, Bureau of Mines, Wash., D. C, 1913. 

2 "Laboratory Manual of Bituminous Materials," by Provost Hubbard, N. Y., 65, 1916. 

'"Petroleum and Its Products," by Boverton Redwood, Volume 2, 577, 1906; "Laboratory 
Manual of Bituminous Materials," by Provost Hubbard, N. Y., 66, 1916. 



520 ASPHALTS AND ALLIED SUBSTANCES 

Test 18. Burning-point. The burning-point is used to supplement 
the flash-point, and is of value in determining the adaptability of 
bituminous substances for particular purposes, from the standpoint of 
fire hazard. The test may be performed in any of the apparatus 
described under flash-point (Test 17), In determining the burning- 
point, the cover of the tester is removed, and the heating, also ex- 
posure to the test-flame continued in the same manner as for the 
flash-point, until the vapors ignite and continue to burn. 

Test 19. Fixed Carbon. This test is used solely for purposes of 
identification, and is generally restricted to asphaltic products rather 
than to tars and pitches, since the free carbon in the latter will inter- 
fere with the results. Accordingly, if this test is performed on tar 
products, the free carbon should be ascertained separately (Test 31) 
and its weight deducted. The percentage of fixed carbon is especially 
useful in differentiating the asphaltites, the asphaltic pyrobitumens, 
and the non- asphaltic pyrobitumens. 

The test is performed in the following manner:^ 1 g. of the material is placed 
in a platinum crucible weighing 20-30 g., having a tightly fitting cover, and heated 
for exactly 7 minutes, with a Bunsen flame 20 cm. high, the mouth of the burner 
being 6-8 cm. below the bottom of the crucible. The test should be made in a 
place free from draughts. The crucible is then transferred to a desiccator, cooled 
and weighed, whereupon the cover is removed, and the crucible ignited over the 
full flame of a Bunsen burner, until nothing but ash remains. Any carbon deposited 
on the cover is also burnt off. The weight of the first residue less the weight 
of ash gives the weight of fixed carbon, which should be calculated in percentage. 
If the ash contains carbonates, it should be treated with a few drops of ammonium 
carbonate solution, and heated a minute or two at red heat, before cooling and 
weighing. 

In the presence of mineral matter, the percentage of fixed carbon should be cal- 
culated on the basis of the non-mineral constituents. Mineral matter does not 
vitiate the results as it merely acts as a diluent. Thus a pure grahamite containing 
0.2 per cent mineral matter and 52.22 per cent fixed carbon, when mixed with an 
equal weight of clay, tested 26.33 per cent, equivalent to 52.7 per cent fixed carbon 
on the basis of the non-mineral constituents present. 

Test 20. Distillation Test. The value of this test is to ascertain 
the adaptability of bituminous materials for a given use, generally for 
road treatment; also for gauging the uniformity of supply, for pur- 
poses of factory control, and most important of all as a criterion of 
the quality. This test is generally applied to tar products as an equiv- 
alent of the volatility test (Test 16). Two methods are generally 
employed, one known as the " Flask Method '' suitable for bituminous 

1 J. Am. Chem. Soc, 21, 1116, 1899; "Fixed Carbon in Bituminous Materials, Its Determina- 
tion and Value in Specifications," by L. Kirschbraun, Eng. Contr , 39, 172, 1913. 



HEAT TESTS 



521 



materials intended for road treatment, including both tars and asphaltic 
products, and another known as the '' Retort Method " for testing 
creosote oil intended for impregnating timber. The bituminous mate- 
rials must be dehydrated (Test 25), before being subjected to distilla- 
tion. According to Sharpies ^ the distillation test as applied to tars 
becomes of value in identifying the kind used (upon determining the 
specific gravity of the fractions distilled), as a means of distinguishing 
a cut-back tar from a straight-distilled tar (upon determining the spe- 
cific gravity of the fractions, their viscosity, also the fusing-point of the 
residue), and for detecting the presence of abnormal amounts of naph- 
thalene. 

Test 20a. Flask Method of Distillation. If water is present, the bituminous 
material must first be dehydrated. This may be conveniently performed by dis- 
tilling 500 c.c. in an 800-c.c. copper still, provided with a 
water-cooled condenser, the distillate being caught in a 
200-c.c. separatory funnel. When all the water is expelled, 
the distillate is allowed to settle, the water dra\Mi off and 
the oils returned to the residue in the still after the con- 
tents have cooled below 212° F. 

The apparatus as assembled is illustrated in Fig. 185. 
It consists of 250-c.c. Engler distilling flask of the follow- 
ing dimensions: diameter of bulb 8.0 cm.; length of neck 
15.0 cm.; diameter of neck 1.7 cm.; surface of material 
to lower side of tubulature 11.0 cm.; length of tubulature 
15.0 cm.; diameter of tubulature 0.9 cm.; angle of tubu- 
lature 75°; with a permissible variation of 3 per cent from 
the foregoing measurements. 

The condenser tube shall have the following dimensions : 
adapter 70 mm.; length of straight tube 185 mm.; A\idth of 
tube 12-15 mm.; width of adapter end of tube 20-25 mm. p^.^^^^ ^ g ^ j^^ Standards 

A carefully standardized thermometer should be used.'- Fig. 185. — Flask Method 
The cylinder used for collecting the distillate shall have of Distillation. 

a capacity of 25 c.c. and be graduated in 0.1 c.c. The 

burner should be provided with a tin shield 20 cm. long by 9 cm. in diameter, 
having a small hole for observing the flam^e. The thermometer bulb should be 
placed opposite the middle of the tubulature. Pour 100 c.c. of the dehydrated 
bituminous material into the Engler flaek and weigh. Then commence to distil 
at the rate of 1 c.c. per minute, changing the receiver as the mercury column 
passes the following fractioning points, reporting the fractions by weight and by 
volume : 




Start to 110° C; 
residue. 



110-170° C; 170-235° C; 235-270° C; 270-300° C; and 



»" Distillation of Tar," J. Ind. Eng. Chem., 6, 466, 1913, 
^Proc. Am. Soc. Testing Materials, 17, Part I, 474, 1917. 



522 



ASPHALTS AND ALLIED SUBSTANCES 



The residue is weighed after the distillation is completed and the flask cooled.^ 
Test 20b. Retort Method of Distillation. This method is adapted principally 
for analyzing creosote oils suitable for impregnating timber.^ The distillation is 
performed in a glass retort, having a Capacity of 250-290 c.c. (measured by placing 
the retort with the bottom of the bulb and the end of the offtake in the same 
horizontal plane and pouring water into the bulb through the tubulature until it 
overflows through the offtake). The length of the offtake should be 25-30 cm., 
its internal diameter next to the bulb approximately 2.85 cm., and the diameter 
at the open end approximately 1.25 cm. The diameter of the tubulature should be 
approximately L9 cm. 




Fig. 186. 



From A. S. T. M. Standards. 
-Asbestos Shield for Retort. 



The condenser tube shall have the following dimensions: diameter of small 
end 12.5 mm. with a variation of 1.5 mm.; diameter of large end 28.5 mm. with a 
variation of 3.0 mm.; length 360 mm. with a variation of 4.0 mm. 

The asbestos shield for the retort shall have the form and dimensions illustrated 
in Fig. 186. The receiver shall consist of Erlenmeyer flasks of 50-100 c.c. capacity, 
and the thermometer shall be carefully standardized.^ 

The apparatus is assembled as illustrated in Fig. 187. Exactly 100 g. of dehy- 
drated creosote oil are distilled at the rate of not less than 1, nor more than 2 drops 
per second, the distillate being collected and weighed in the receiver. The condenser 
tube should be warmed whenever necessary to prevent the accumulation of solid 
distillate, and the receiver changed as the mercury passes the dividing temperatures 
of the following fractions: 210, 235, 270, 315 and 355° C. When the temperature 



1" Standard Method for Distillation of Bituminous Materials Suitable for Road Treatment," 
(Serial Designation; D 20-16) 1916 Book of A. S. T. M. Standards, 540. 

'"Standard Method for SampUng and Analysis of Creosote Oil" (Serial Designation; D 38- 
17) A. S. T. M. Standards Adopted in 1917, 30. 

'"Standard Methods for Sampling and Analysis of Creosote Oil" (Serial Designation: D 38-17) 
A. S. T. M, Standards Adopted in 1917. 36. 



HEAT TESTS 



523 



registers 355*^ C, the flame shall be removed from the retort, and any oil which 
has condensed in the offtake drained into the 355° fraction. The retort is cooled 



■ Thermometer 




From A. S. T. M. Standards. 

Fig. 187.— Retort Method of Distillation. 



and reweighed to ascertain the amount of residue, which is generally tested by the 
float test (Test M). The various fractions should be reported by weight and also 
by volume, and their specific gravities calculated. 



CHAPTER XXX 
SOLUBILITY TESTS 

Test 21. Solubility in Carbon Disulphide. The percentage soluble 
in carbon disulphide is useful for purposes of identification, for ascer- 
taining the adaptability of a bituminous substance for a given purpose, 
for gauging its uniformity of supply, and as a criterion of its quality, 
(i.e., purity, and consequently its intrinsic value). Crude bituminous 
materials are often purchased on the basis of the percentage soluble in 
carbon disulphide. The presence of non-mineral matter insoluble in 
carbon disulphide is an indication that the material has been carelessly 
prepared and overheated in its process of manufacture. The presence 
of mineral matter may be regarded as an adulterant. In the case of 
native asphalts, the larger the percentage soluble in carbon disulphide, 
the greater their intrinsic value. The percentage and composition of 
the mineral matter will often indicate the source of the native asphalts. 
Asphalts derived from petroleum are substantially free from mineral 
constituents, and with the possible exception of the harder grades, con- 
tain little to no non-mineral matter insoluble in carbon disulphide. 
This test is sometimes employed for determining the value of tars and 
pitches, although the solubility in hot benzol-toluol is generally used 
for this purpose (Test 24). 

With native asphalt containing over 10 per cent of mineral matter, 
it is ad isable to separate the portion soluble in carbon disulphide for 
ascertaining its physical characteristics (Tests 1-12), fusing-point (Test 
15), and sometimes fixed carbon (Test 19). 

Test 21a. Solubility in Carbon Disulphide. The tests generally employed for this 
purpose have been devised by the Am. Soc. Testing Materials^ and are substantially 
as follows, deviating slightly in phraseology. 

The bituminous material should first be freed from moisture. If semi-solid 
to solid it may be heated in an oven 125° C. for 1 hour, provided it is substantially 
free from volatile matter at this temperature. If volatile materials are present, 
it should be dehydrated by distillation at a low temperature, and the water-free 
distillate returned to the residue, and thoroughly incorporated with it. 

» "Standard Teat for Soluble Bitumen" (Serial Designation D 4-11), A. S. T. M. Standards 
Adopted in 1916, 528; "Tentative Specifications for Asphalt for Use in Damp-proofing and Water- 
proofing" (Serial Designation: D 40-17 T), Proc. Am. Soc. Testing Materials, 17, Part I, 714, 1917. 

524 



SOLUBILITY TESTS 525 

Sufficient of the dehydrated material to insure the presence of 1-2 g. soluble in 
carbon disulphide is weighed into a 150-c.c. tared Erlenmeyer flask, and 100 c.c. 
of c.p. carbon disulphide poured into the flask in small portions, with continuous 
agitation until all the lumps disappear and nothing adheres to the bottom. The flask 
is then loosely corked and set aside. From this point on, one of two methods may 
be follov/ed, depending on whether or not the bituminous material contains a sub- 
stantial quantity of finely divided insoluble matter. 

Procedure Used in the Presence of Substantial Quantities of Finely Divided Insol- 
uble Matter. The flask is set aside to settle for 48 hours, and the solution decanted 
into a second tared flask, pouring off as much of the solvent as possible without 
disturbing the residue. The contents of the first flask are again treated with a 
quantity of carbon disulphide, shaken as before, and both the first and second 
flasks allowed to settle for another 48 hours. The liquids in both flasks are then 
carefully decanted upon a weighed Gooch crucible (measuring 4.0 cm. wide at the 
top, tapering to 3.6 cm. at the bottom, and 2.5 cm. deep), carrying freshly ignited 
long-fibered amphibole (asbestos) compacted in a layer not over | in. No vacuum 
is to be used in filtering, and the temperature of the Hquid kept between 20 and 
25° C. The residue remaining on the filter is thoroughly washed with carbon 
disulphide until the filtrate becomes clear. The flasks are again shaken with fresh 
carbon disulphide, allowed to settle for 24 hours, or until it is seen that a good 
subsidation has taken place, and thereupon decanted through the filter. The 
residues remaining in both flasks are washed until the washings are practically 
colorless, all washings being passed through the Gooch crucible. 

Procedure Followed with Materials Containing Little to no Finely Divided Insol- 
uble Matter. This method is used for rapid work where the bituminous material 
does not contain insoluble matter which would clog the pores of the filter. After 
adding the carbon disulphide, the flask is set aside for 15 minutes, whereupon it is 
filtered through a weighed Gooch crucible. The liquid must be decanted with 
care, and the decantation stopped at the first sign of sediment coming over. The 
sides of the flask are washed with a small amount of fresh carbon disulphide, and 
the sediment caught on the filter, using a " policeman," if necessary, to remove all 
adhering material. Then wash residue on filter with carbon disulphide until the 
washings are colorless, and continue the suction until the odor of carbon disulphide 
is scarcely detectable. The outside of the crucible is cleaned by a cloth moistened 
with a small amount of the solvent. 

In both procedures, the crucible and contents, likewise the two flasks in the 
first method, are heated for one-half hour at 220° F., cooled in a desiccator and 
weighed. The difference between the weight of the dehydrated material taken 
for analysis and the weight of the residue, represents the proportion soluble in 
carbon disulphide.^ 

The author finds that in the presence of large quantities of finely divided insol- 
uble matter, the method may be materially shortened by adding a weighted quan- 
tity (about twice the weight of bituminous material) of freshly ignited, long-fibered 

> For a discussion of the method, see "A Study of Certain Methods for Determining Total 
Soluble Bitumen in Paving Materials," by S. Avery and R. Corr, J. Am. Chem. Soc, 28, 648, 1906; 
"The Proximate Composition and Physical Structure of Trinidad Asphalt, with Special Reference 
to the Behavior of Mixtures of Bitumen and Fine Mineral Matter," by Clifford Richardson, 
Proc. Am. Soc. Testing Materials, 6, 509, 1906; "The Determination of Soluble Bitumen," by 
Hubbard and Reeve, Proc. Am. Soc. Testing Materials, 10, 420, 1910; "The Bitumen Content of 
Coarse Bituminous Aggregates," by Prevost Hubbard, Proc. Int. Assoc. Testing Materials, XXV-2, 
1912. 



526 ASPHALTS AND ALLIED SUBSTANCES 

amphibole to the bituminous substance in the first flask. On shaking with carbon 
disulphide, the asbestos serves to dilute the insoluble matter, preventing the latter 
from clogging the pores of the filter, and accordingly reducing the time of filtration. 
In many cases this procedure may be adopted to good advantage. 

Test 21b. Non-Mineral Matter Insoluble in Carbon Disulphide. The total 
weight of the insoluble matter obtained in the foregoing test, includes both the 
non-mineral matter insoluble in carbon disulphide, and the mineral matter. The 
former is determined by igniting the residue in the Gooch crucible (to which must 
be added the residues remaining in the flasks) until no carbonaceous particles 
remain, leaving only the mineral ash. Add a few drops of ammonium carbonate 
solution to the residue, ignite for a few minutes at a red heat, cool in a desiccator, 
and weigh. The loss in weight on ignition represents the " non-mineral matter 
insoluble in carbon disulphide." 

Test 21c. Mineral Matter. The residue obtained in the foregoing test repre- 
sents the mineral constituents. When calcium carbonate is present it is necessary 
to ignite the residue with ammonium carbonate before finally weighing, as it is claimed 
that any sulphur present in the bituminous material reacts with the calcium car- 
bonate forming calcium sulphate and calcium sulphide.^ The loss of any water of 
hydration from clays, etc., and the oxidation of iron p3Tites to ferric oxide, will 
also affect the results (see p. 534). The mineral matter may be checked by igniting 
a fresh sample in a platinum crucible to clean ash, adding a few drops of ammonium 
carbonate, re-igniting and weighing. If the two results do not agree, evaporate the 
filtrate containing the bituminous matter soluble in carbon disulphide (Test 21a), 
bum, ignite and weigh the residue. The weight of the ash derived from the 
bituminous matter soluble in carbon disulphide should be added to the original 
residue of insoluble mineral matter (Test 216). This may represent collodial 
mineral particles, which are not retained by the filter, or else mineral constituents 
combined chemically with the bituminous matter (see p. 539). 

Test 22. Carbenes. The expression " carbenes " has been applied 
to that portion of bituminous substances soluble in carbon disulphide 
but insoluble in carbon tetrachloride. This term was originally pro- 
posed by Cliflford Richardson. ^ This test is of value in identifying 
bituminous substances, gauging their uniformity of supply, for purposes 
of factory control, and as a criterion of their quaUty. Certain hard 
native asphalts and asphaltites, particularly grahamite, normally con- 
tain a percentage of carbenes, whereas petroleum asphalts do not show 
carbenes unless they are overheated, or over-blown. If more than 0.5 
per cent is present in petroleum asphalts, their quality is to be regarded 
as questionable. Carbenes are found in tars and pitches in varying 
amounts.^ 

» "Analysis of Calcareous Asphaltum and Paving Mixtures," by Prettner, Chem. Zeit., 33, 917 
and 926, 1909. 

2 "Carbon Tetrachloride and its Use as a Solution for Differentiating Bitumens," by Clifford 
Richardson and C. N. Forrest, J. Soc. Chem. Ind., 24, 310, 1905. 

8 "Some Relations of the Effect of Overheating to Certain Physical and Chemical Properties 
of Asphalts," by A. W. Hixson and H. E. Hands, J. Ind. Eng. Chem., 9, 651, 1917; "The Value 
of the Carbene Requirement in Asphalt Specifications," by L. Kirschbraun, Munic. Eng., 30, 349, 
1909. 



SOLUBILITY TESTS 527 

This test is carried out by following the same procedure as in determining the 
solubihty in carbon disulphide (Test 21a), but replacing the latter with carbon 
tetrachloride. The carbon tetrachloride must be free from carbon disulphide, 
which may be insured by distilling it under a dephlegmator, discarding any distillate 
below 76° C. The solvent is then filtered through calcium chloride, and any free 
hydrochloric acid removed by blowing dry air through it. 

The carbon tetrachloride is allowed to act on the bituminous substance over- 
night, care being taken to keep the vessel in a dark place to protect it from day- 
light or sunshine.^ Richardson proposes blowing a gentle current of air through the 
solution in the dark for 1 hour^ to coagulate the insoluble matter and assist in the 
filtration. The difference between the percentages soluble in carbon disulphide and 
carbon tetrachloride respectively, represents the per cent of " carbenes." 

Test 23. Solubility in 88° Petroleum Naphtha. This test is em- 
ployed mainly for purposes of identification. It is also used to a cer- 
tain extent for determining the adaptability of a bituminous substance 
for a given use, for gauging the uniformity of supply, and for purposes 
of factory control. As a general principle, the harder the bituminous 
product, the smaller the percentage that will dissolve in 88° naphtha. 
Asphaltites are relatively insoluble in this menstruum. Mineral waxes, 
peat-, lignite- and shale tars or pitches are largely soluble. The solu- 
bility of native and petroleum asphalts varies, depending largely upon 
their hardness, and also in the case of petroleum asphalts upon the extent 
to which the distillation has been driven. Coal-tar pitches are relatively 
insoluble in 88° naphtha. 

The portion soluble in 88° naphtha has been termed ^' petrolenes " by 
some, and " malthenes '' by others, whereas the non-mineral constituents 
insoluble in 88° naphtha are generally referred to as '* asphaltenes." 

It is important that the petroleum naphtha should be derived from petroleum 
composed entirely of open-chain hydrocarbons, and test exactly 88° Baume, equiv- 
alent to a specific gravity of 0.638 at 60° F./60° F. At least 85 per cent by 
volume should distil between 95 and 150° F. The density and character of the 
naphtha is important, since heavy distillates, or products derived from petroleum 
containing unsaturated or cyclic hydrocarbons will exert a greater solvent action upon 
the bituminous substance (see p. 467). 

This method is performed in the same manner as for determining the portion 
soluble in carbon disulphide, 88° petroleum naphtha being substituted for the latter. 
Hard bituminous substances should be powdered; liquid bituminous substances 
flowed in a thin layer over the bottom of the flask; and semi-solid to semi- 
liquid subtances heated until fluid and distributed in a thin layer to present a 
greater surface to the solvent. It is advisable not to use a stirring rod, as this 
causes the bituminous substance to adhere to the inner surface of the flask and to 
the rod itself. The operation should take place at room temperature, and away 

1 "Studies on the Carbenes," by K. J. Mackenzie, J. Ind. Eng. Chem., 2, 124, 1910; "On the 
Formation of Carbenes," by D. B. W. Alexander, J. Ind. Eng. Chem., 2, 242, 1910. 
»"The Modern Asphalt Pavement," 2nd Edition, 546, 1908. 



528 ASPHALTS AND ALLIED SUBSTANCES 

from the direct rays of the sun. The introduction of a weighed portion of long- 
fibered asbestos to the solution will assist in its filtration. ^ 

Test 24. Solubility in Other Solvents. Solvents other than those 
mentioned in the foregoing tests, such as benzol, mixtures of benzol 
and toluol (Test 31), acetone (see p. 193), etc., are occasionally used 
for identifying bituminous substances or to investigate their adapta- 
bility for a given use. The extraction may be carried out cold or hot, 
but in either event the method used should be clearly stated in report- 
ing the results. If cold, follow the method described under Test 
21a, for determining the portion soluble in carbon disulphide. If hot, 
weigh out approximately 10 g. of the bituminous substance into a 
paper thimble, and treat with the solvent in a Soxhlet extractor having 
ground-glass joints. Hard and brittle bituminous substances should be 
powdered. Medium and soft substances should be mixed with five 
times their weight of long-fibered amphibole (previously ignited), or 
ten times their weight of 20- to 30-mesh Ottawa silica to prevent the 
material fusing together in a solid mass and retard the action of the 
solvent. 

Where the hot extraction is used, the operation is continued for at least 6 
hours, and until no further loss in weight is recorded, whereupon the contents of 
the thimble are dried and weighed. 

i"The Modern Asphalt Pavement," by Clifford Richardson, 2nd Edition, p. 543, 1908; 
"Laboratory Manual of Bituminous Materials," by Hubbard, 1st Edition, p. 90, 1916. 



CHAPTER XXXI 

CHEMICAL TESTS 

Test 25. Water. The estimation of water is made in some cases for 
purposes of identification, and in others as a criterion of the quaUty, 
Native asphalts and tars are examined in this way to ascertain whether 
they exist in the crude or the dehydrated state. This test is also used for 
dehydrating bituminous substances to render them suitable for further 
examination, where the presence of water would interfere. 

Test 25a. Substances Distilling at Low Temperatures. This method is adapted 
to crude petroleum, tars, creosote oil and other fluid bituminous substances dis- 
tilling at comparatively low temperatures.^ The apparatus is set up as shown 
in Fig. 188. The copper still is provided with a removable flanged top and yoke, 



• Thertnomehf 




Fig. 188. 



From A. S. T. M. Standards. 
-Still for Determining Water. 



which with a paper gasket will form an air-tight joint when clamped into place. 
The thermometer should be carefully standardized, as provided in the Am. Soc. 
Testing Matsrials Stindards, 1917, p. 37. The condenser consists of a copper 
trough carrying a straight- walled glass tube. The separatory funnel has a total 
capacity of 120 c.c. with the outlet graduated in fifths of a cubic centimeter. 

1 " Standard Methods for Sampling and Analysis of Creosote Oil " (Serial Designation: D 38-17), 
A. S. T. M. Standards, Adopted in 1917, 31. 

529 



530 ASPHALTS AND ALLIED SUBSTANCES 

Pour 200-500 c.c. of the bituminous material into the still and weigh. Clamp 
the top in place, using a paper gasket moistened with lubricating oil. Apply heat 
with the ring burner supported just above the level of the bituminous material at 
the beginning of the test, and then gradually lower it as the water distils over. 
Continue the distillation until the vapor temperature reaches 205° C, Collect the 
distillate in the separatory funnel, and let it stand until a clean separation of water 
takes place. Read off the volume of water, calculate its weight, and figure the 
per cent present in the crude bituminous material. Draw off the water, and return 
any light oil to the bituminous matter in the still. The dehydrated material should 
then be used for further tests. 

Test 25b. Substances Distilling at High Temperatures. This method is adapted to 
asphalts and other bituminous substances comparatively free from volatile constituents, 
and incapable of distiUing without suffering decomposition. 

Substances Fusing below 300° F. When it is desired to determine the per- 
centage of moisture without using the residue for other purposes, a convenient 
method consists in weighing 100 g. into a distilHng flask, adding 200 c.c. of kerosene 
in the case of asphaltic products, or toluol in the case of tar products, and warming 
gently under a reflux condenser until the bituminous substance mixes with the 
solvent. Cool, add a quantity of dry pumice-stone to prevent bumping, and distil 
into a graduate until the hquid comes over clear. The distillate is then allowed to 
settle by gravity, and the volume of water read off directly; or else the water may 
be withdrawn with a pipette, and weighed. This method is said to be accurate 
to approximately 0.033 g. of water per 100 c.c. of toluol or kerosene present in the 
distillate.^ 

Where the hydrated material is to be used for further examination, 25 g. are 
weighed into an Erlenmeyer flask, through which a current of dry illuminating gas 
is passed, and maintained at 105° C. for 1 hour. The vapors are led through a 
return condenser maintained at 50° C, and then into a weighed calcium chloride 
tube. When all the moisture is driven off, the calcium chloride tube is re weighed 
and the moisture calculated. If constituents are present volatilizing below 50° C, 
the return condenser should be maintained at a corresponding lower temperature. 

Substances Fusing above 300° F. In this case the material is comminuted by 
powdering (to about 60 mesh) or shaving, and a weighed quantity spread in a 
thin layer on glass and maintained in an oven at 125° C. for 1 hour, or until the 
weight becomes constant. If the substance is oxidizable in air, it should be heated 
in an atmosphere of illuminating gas. Cool in a desiccator, reweigh and calculate 
the per cent moisture. 

Tests 26. Carbon, and 27. Hydrogen. Carbon and hydrogen are 
grouped together, because both are generally determined simultaneously. 
These are of value in establishing the identity of bituminous materials, 
in connection with the corresponding percentages of sulphur, nitrogen 
and oxygen. 

The electrical combustion method is now used almost exclusively for determining 
carbon and hydrogen. A weighed quantity of the material is caused to undergo 
combustion and the gaseous products are thoroughly oxidized by being passed over 

1 *' Methods for the Determination of Water in Petroleum and its Products," by I. C. Allen 
and W. A. Jacobs, Tech. Paper 25, Dept. of Interior, Bureau of Mines, Wash., D. C, 1912. 



CHEMICAL TESTS 



531 



m\ 



4 




^^ 



^ 



B 



red-hot copper oxide and lead chromate. The water generated is absorbed in a 
weighed Marchand calcium-chloride tube, and the carbon dioxide in a weighed 
Liebig bulb containing a 30 per cent solution of potassium hydroxide. A furnace 
of the Heraeus type (Fig. 189) consisting of electrical heaters a, b, and c; two of 
which, namely, a and b are mounted on sheave wheels running on a track so they 
may be moved along the combustion tube; the third heater c being stationary and 
constructed by winding an alundum or fused quartz tube 
12 cm. long with No. 16 nichrome II wire, and enclosed in 1^ 

a cylinder packed with magnesia-asbestos. Heater c sur- 
rounds the lead chromate in the combustion tube. The 
movable heaters a and b have thin platinum foil (weighing 
about 9 g. in aU) wound on a porcelain or fused quartz 
combustion tube of 30 mm. internal diameter. The large 
heater 6, 350 mm. long, surrounds the copper oxide, and 
the smaller one a, 200 mm. long, heats the sample in the 
boat. The combustion tube d of Jena glass or fused silica, 
measuring 21 mm. external diameter and 900 mm. long, is 
supported by an asbestos-hned nickel trough e. The current 
through each heater is regulated by separate rheostats / 
and g, the heating coils a and b requiring about 4.5 amperes 
at 220 volts. 

The furnace is arranged so either air or oxygen may 
be passed through the combustion tube, and is equipped 
with two purifying trains in dupHcate (of which but one is 
shown in the figure) connected to the combustion tube by 
a Y-tube, the joint being made tight by a rubber stopper. 
The purifying apparatus H contains the following reagents 
in order of the passage of the air or oxygen through them: 
sulphuric acid i, for removing any traces of ammonia; a 
30 per cent potassium hydroxide solution j; granular soda- 
lime k; and granular calcium chloride l. One of the puri- 
fying trains is connected directly with an oxygen tank 
provided with a reducing valve for regulating the pressure, 
and the other being used for purifying the air supply, which 
is drawn through the apparatus by an aspirator connected 
with the other end of the combustion tube. 

The first 30 cm. of the combustion tube are empty; then 
comes an asbestos plug (acid-washed and ignited) ; the next 
40 cm. are filled with copper oxide gauze; then a second as- 
bestos plug; then 10 cm. of fused lead chromate; and finally 
another asbestos plug 20 cm. from the end of the tube. 

The absorption train consists of a 4-in. U-tube m filled 
with granular calcium chloride (previously saturated with 
carbon dioxide) to absorb the moisture. This in turn is 

connected to a Vanier potash bulb n containing a 30 per cent potassium hydroxide 
solution and granular calcium chloride. The potash bulb is connected with an 
aspirator through the guard-tube o containing granular calcium chloride and soda- 
lime. A Mariotte flask p, serves to keep the suction constant. 

It is important to see that all connections are made tight. Before starting a 



532 ASPHALTS AND ALLIED SUBSTANCES 

determination or after any changes in chemicals or connections, a blank test should 
be run by aspirating 1 liter of air through the apparatus, which is heated in the 
same manner as though a determination were being made. If the Vanier bulb n 
or the calcium chloride tube m show a change in weight of less than 0.5 mg. each, 
the apparatus may be considered in a satisfactory condition. 

Approximately 0.25 g. of the bituminous substance is carefully weighed into a 
porcelain or platinum boat and transferred to the combustion tube which should be 
cool for the first 30 cm., the copper oxide at a bright-red heat, and the lead chro- 
mate at a dull-red heat. The boat should be introduced rapidly near the asbestos 
plug at the beginning of the copper oxide, the stopper connecting with the purifying 
train replaced and pure oxygen passed through at the rate of 3 bubbles per second. 
The current is gradually turned on heating coil a, which at the start should be at 
the right of the boat. By manipulating the rheostat, and gradually pushing the 
coil towards the boat, the evolution of volatile matter is carefully controlled to 
prevent too rapid an evolution of gas and tar, which may either escape complete 
combustion or be driven back into the purifying train. The heat should accord- 
ingly be increased slowly by manipulating the rheostat, until the sample ignites, 
whereupon the temperature may be increased rapidly. Any moisture collecting 
in the end of the combustion tube or in the rubber connection joining it to the 
calcium-chloride tube m is driven into the latter by carefully warming with a hot 
tile. After the sample ceases to glow, the oxygen is continued for 2 minutes, 
whereupon the heat is turned off, and 1200 c.c. air aspirated through the train. 
The absorption bulbs are disconnected, wiped clean, allowed to cool and weighed. 
The percentage of carbon is equal to the increase in weight of the KOH bulb (n) 
multiplied by 27.27 and divided by the weight of the sample. The percentage of 
hydrogen is equal to the increase in weight of the CaCU tube (m) multiplied by 
11.19 and divided by the weight of the sample.^ 

Test 28. Sulphur. This test is also used for differentiating and identify- 
ing bituminous substances. 

A number of methods have been proposed for this purpose, but the most rapid 
and accurate one consists in igniting about 1 g. of the material in an approved 
form of bomb calorimeter, preferably of the Berthelot type (500-600 c.c. capacity), 
containing 10 c.c. of water and filled with oxygen under a pressure of 30 atmos- 
pheres. The bituminous substance is weighed on a small lump of chemically pure 
cotton (free from sulphur) and placed on a small platinum cone, which in turn is 
suspended from a copper wire. The cotton is connected with a thin platinum wire 
forming a short-circuit between the suspended copper wire and the return conductor. 

After the combustion has taken place, the bomb is allowed to cool for 15 
minutes, then opened up and its contents washed into a beaker. If the bomb has 
a lead washer, 5 c.c. of a saturated solution of sodium carbonate should be added, 
and the contents boiled for 10 minutes to decompose any lead sulphate emanating 
from the washer. The solution is then filtered, washed, acidified with 5 c.c. of 
dilute hydrochloric acid (1 : 2), boiled to expel any carbon dioxide, and precipitated 
with 20 c.c. of a hot 5 per cent solution of barium chloride. The solution is allowed 

1" Methods of Analyzing Coal and Coke," by F. M. Stanton and A. C. Fieldner, Tech. Paper 
8, Dept. of Interior, Bureau of Mines, Wash., D. C, 1913. " Standard Methods for Laboratory 
Sampling and Analysis of Coal " (Serial Designation: D 22-16), A. S. T. M. Standards, Adopted 
1916, 565. 



CHEMICAL TESTS 533 

to stand for at least 2 hours at a temperature just below its boiling-point, and the 
following day is filtered through an ashless paper and washed with pure hot water 
until a drop of the filtrate shows no precipitate with silvei nitrate solution. 
The test for excess of barium chloride is made by adding a few drops of sulphuric 
acid to the filtrate. The precipitate is then ignited in a weighed fused silica cru- 
cible, cooled and weighed. The weight of the barium sulphate multiplied by 13.74, 
divided by the weight of the sample is equal to the percentage of sulphur present. ^ 
The Eschka method for determining sulphur is not recommended for bituminous 
materials. 

A rapid test for detecting the presence of sulphur qualitatively, ^ consists in 
dissolving 10 g. of the substance in 25 c.c. benzol with gentle heating, cooling and 
adding 30 c.c. N/2 alcoholic potash, shaking, and then rapidly diluting with 200 c.c. 
96 per cent alcohol. After standing a short time, the hquid (which should test 
alkaline to phenolphthalein) is decanted. The residue is washed with alcohol, 
dried on a water bath and finally at lOS'' C. It is then heated with 100 cc. of 
ether under a reflux condenser, and a few lumps of granular calcium chloride are 
added. After cooling, the liquid is filtered into a test tube to remove any insoluble 
matter present, and the solution mixed with 20 c.c. 2 per cent mercuric bromide 
m ether, and allowed to stand overnight. If a precipitate forms, it is filtered off, 
washed with ether, and dissolved from the filter paper with warm benzol. If any 
sulphur-bearing bituminous substances are present, including petroleum or native 
asphalts, the precipitate will dissolve in the benzol forming a dark brown solution 
(any mercurious bromide present remaining undissolved). On evaporating the 
benzol, the mercuric-bromide-sulphur-compound is deposited as a dark brown to 
black brittle mass. 

Test 29. Nitrogen. This determination is also used for identifying 
bituminous products, and the procedure ordinarily employed constitutes 
the well-known Kjeldahl-Gunning method.^ 

One gram of the bituminous material, which should be finely powdered when suffi- 
ciently hard, is boiled with 30 c.c. of concentrated sulphuric acid, 7-10 g. of potas- 
sium sulphate, and 0.6-0.8 g. of metalHc mercury in a 500-c.c. Kjeldahl flask until 
the material is completely oxidized and the solution becomes clear. The boiling 
should be continued at least two hours after the solution reaches the straw-colored 
stage, the total time required ranging from 3 to 4 hours. After the solution has 
cooled, a few crystals of potassium permanganate are added to insure complete 
oxidation. When thoroughly cool, the solution is diluted to 200 c.c. with cold 
water, again cooled, and the following solutions added: 25 c.c. of a 4 per cent 

i"The Sulphur Content of Fuels, and Especially Petroleum Products," by I. C. Allen and 

I. W. Robertson, Tech. Paper 26, Bureau of Mines, Dept of Interior, Wash., D. C, 1912; "Sul- 
phur in Tar Residues," by Prevost Hubbard and C. S. Reeve, Proc. Am. Soc. Testing Materials, 

II, 666, 1911; "The Detection and Determination of Sulphur in Petroleum," by C. K. Francis 
and C. W. Crawford, J. Jnd. Eng. Chem., 9, 479, 1917. 

2 "J, Marcusson, "The Composition and Examination of Residues from Fat Distillation," 
loc. cit. 

3 "Methods of Analyzing Coal and Coke," by F. M. Stanton and A. C. Fieldner, Tech. Paper 8, 
Bureau of Mines, Dept. of Interior, Wash., D. C, 1913; "Determination of Nitrogen in Coal," 
by A. C. Fieldner and C. A. Taylor, Tech. Paper 64, Bureau of Mines, Dept. of Interior, Wash., 
D. C, 1915, "Standard Methods for Laboratory Sampling and Analysis of Coal" (Serial Designa- 
tion: D 22-16); A. S. T. M. Standards, Adopted 1916. 570. 



584 ASPHALTS AND ALLIED SUBSTANCES 

solution of potassium sulphide to precipitate the mercury; 1-2 g. of granular zinc 
to prevent bumping; and finally enough saturated sodium hydroxide (usually 
80-100 c.c.) to make the solution distinctly alkaline. The danger of losing ammonia 
may be minimized by holding the flask in an inclined position while the sodium 
hydroxide solution is being added and carefully running the alkaline solution down 
the side of the flask bo it will form a layer below the acid solution. The flask 
should then be at once connected with the condensing apparatus, and the solution 
mixed by gently rotating the flask. 

The ammonia is then distilled into 10 c.c. of standard sulphuric acid solution 
at the rate of 100 c.c. per hour, until 150-200 c.c, of distillate have passed over. 
The distillate is then titrated with standard ammonia or caustic soda solution, 
using cochineal as indicator with the former, or methyl orange with the latter (20 
c.c. standard ammonia or caustic soda solution are equal to 10 c.c. of standard 
sulphuric acid, and also equivalent to 0.05 g. nitrogen). 

Test 30. Oxygen. There being no satisfactory direct method for 
determining oxygen, it is computed by subtracting the sum of the per- 
centages of hydrogen, carbon, nitrogen, sulphur, water and ash from 
100 per cent. The result so obtained is affected by all the errors 
incurred in the other determinations, and especially by the change in 
weight of the ash-forming constituents on ignition. Iron pyrites will 
absorb oxygen from the air and change to ferric oxide, increasing the 
weight of ash, and thereby causing a negative error in the oxygen, 
equivalent to three-eighths of the pyritic sulphur. Any calcium car- 
bonate present will tend to absorb sulphur combined with the bitu- 
minous constituents (p. 526). On the other hand, there is always a 
loss on ignition of 'Svater of composition" from the clayey and shaley 
constituents, also carbon dioxide from carbonates, etc., which tend to 
compensate for the absorption of oxygen.^ 

Test 31. Free Carbon in Tars. This represents an adaptation of 
Test 24 suitable for testing tars and pitches for the presence of non- 
mineral matter insoluble in hot toluol-benzol, which has been found 
the most satisfactory menstruum for this purpose. ^ This test is of 
value for purposes of identification, for ascertaining the adaptability 
of the tar or pitch for a given purpose, and for gauging the uniformity 
of supply. Tars and pitches containing large percentages of free carbon 
are objectionable for certain purposes of manufacture, since the free 
carbon acts as so much inert matter, and furthermore is insoluble in 
all solvents. 

» " Standard Methods for Laboratory Sampling and Analysis of Coal " (.Serial Designation: 
D 22-16), A. S. T. M. Standards, Adopted 1916, 571. 

2 "Free Carbon in Tars," by J. M. Weiss, J. Ind. Eng. Chem., 6, 279, 1914; "Some Effects of 
Certain Solvents on Tars in the 'Free Carbon' Determination," by G. S. Monroe and H. J. 
Broderson, J. Ind. Eng. Chem., 9, HOG, 1917. 



CHEMICAL TESTS 



535 



V^ahr Ouflef 

-Hook to Support- Wir* 

-Condenser 

■Cap of Fi Iter Paper or 
^ Alundum Ware . 

..■Filter Cup 

— Wire Support For 
filter Cup 



The apparatus used was devised by H, J. Cary-Curr ^ and is illustrated in Fig. 
190. The filtering medium may consist either of a paper thimble or two thicknesses 
of Schleicher & Schuell's No. 575 hardened filter paper, 15 cm. in diameter, arranged 
in the shape of a cup by folding symmetrically around a stick 1 in. in diameter. It 
should be soaked in benzol to remove any grease, 
dried in an oven, desiccated and weighed. 

Tars must be dehydrated before extracting, 
and pitches if sufficiently hard, ground to a fine 
powder. In testing materials containing more than 
5 per cent of free carbon, 5 g. should be used, 
and 10 g. with smaller percentages. Weigh a 
suitable amount in a 100-c.c. beaker and digest 
with 50 c.c. c.p. toluol on a steam bath with 
constant stirring for not exceeding 30 minutes. 
Place the prepared filter paper in a carbon filter- 
tube and decant the toluol extract through it. 
Wash with hot c.p. toluol until the filtrate is clear, 
using a policeman unaffected by toluol for detaching 
any free carbon adhering to the beaker. Finally 
wash the filter with hot c.p. benzol, and after 
draining, cover it with a cap of filter paper or 
alimdum ware, and extract it in the apparatus 
with c.p. benzol until the drippings become color- 
less. This will take at least 2 hours. The filter 
is then removed, the cap taken off, the paper 

dried in a steam oven, cooled in a desiccator and weighed. With pitches it is well 
to examine the free carbon for foreign matter, such as wood slivers, pieces of 
bagging, etc. If such foreign matter is present, the test should be rejected. ^ 




[<— 6Scm. ->| 



From A. S. T. M. Standards. 
Fig. 190.— Cary-Curr Extrac- 
tion Apparatus. 



Test 32. Naphthalene in Tars. Naphthalene is present in tars and 
pitches generated at high temperatures, including those derived from 
coal. It is produced by the condensation of two or more hydrocarbon 
molecules accompanied by the elimination of hydrogen. (See p. 227.) 
The following test is used solely for purposes of identification: 

One hundred c.c. of tar, or 100 g. of pitch are weighed into a tared Engler 
flask, and distilled by the flask method (Test 20a, p. 521). With tars the dis- 
tillation is continued imtil 95 per cent has been distilled off, and in the case of 
pitches it is stopped when the temperature reaches 355° C. The time of distillation 
should occupy about 20 minutes, and the condenser tube heated to prevent the dis- 
tillate from solidifying in it. The distillate is caught in a separatory funnel, the 
lower portion of which is graduated. This is immersed in water at 60° C. and 
a reading taken, whereupon 50 c.c. of a 10 per cent caustic soda solution are 
added, shaken, allowed to settle, and the clear soda drawn ofT. The contents are 
warmed again to 60 ° C, and the loss in volume noted. Shake with another 30 c.c. 



ij. Ind. Eng. Chem., 4, 535, 1912. 

2 " Tentative Specifications for Coal-tar Pitch for Use in Damp-proofing and Waterproofing,' 
(Serial Designation: D 42-17 T), Proc. Am. Soc. Testing Materials, 17, Part I, 719, 1917. 



536 ASPHALTS AND ALLIED SUBSTANCES 

of soda, and observe whether there is any further diminution in volume. If so, 
repeat until no further shrinkage occurs. The total shrinkage represents the tar 
acids present in the distillate. 

The oil which is unacted upon is placed in a copper beaker maintained at 60° F. 
for 15 minutes, and the separated naphthalene filtered on a paper in a perforated 
funnel, using suction. The naphthalene is pressed between several sheets of filter 
paper in a letter press to remove the adhering oil, weighed, and its percentage 
calculated. 

Test 33. Solid Paraflines. Until recently, it was considered that the 
presence of paraffine was an indication of the quality of asphaltic 
products, and many specifications stipulated the maximum percentage 
permissible. It is now generally conceded, however, that there is no 
rational bearing between the solid parafiines in asphaltic products and 
their quality. The determination of paraffine is therefore of value 
only for purposes of identification. Solid paraffines are never found in 
asphaltites, rarely in natural asphalts, and only traces in asphalts pro- 
duced from strictly asphalt-base petroleums. On the other hand, more 
or less paraffine is present in asphalts derived from non-asphaltic and 
mixed-base petroleums. It is absent in tars and pitches derived from 
high temperature distillation processes (see table p. 483). 

The following method does not give absolute figures, since it merely discloses 
the paraffine hydrocarbons which are solid at room temperature, without taking 
the liquid paraffines into consideration; nevertheless the results are of value for 
purposes of comparison, ^ Weigh 50 g. of the material in a tared 6-oz. glass retort, 
and slowly distil until nothing but a residue of coke remains. The distillation 
should take in the neighborhood of 45 minutes from the time the first drop comes 
over. The distillate is caught in an Erlenmeyer flask, and weighed. Either 5 or 
10 g. of the well mixed distillate, depending upon the quantity of solid parafiines 
present in the crude material, are transferred into a large test tube and dissolved 
in 25 c.c. of absolute ethyl ether and 25 c.c. of absolute ethyl alcohol; A similar 
mixture containing 25 c.c. each of ether and alcohol is made up, and this together 
with the oil solution is cooled separately to exactly 0° F. for ^ hour in a mixture 
of ice and salt (to which if necessary calcium chloride may be added) . The oil 
solution is then rapidly filtered through a weighed Gooch crucible, similarly main- 
tained at 0° F. by a jacket of ice and salt, and washed with 50 c.c. of the cooled 
ether-alcohol mixture. A simple and convenient apparatus consists of an inverted 
bottle 6 in, in diameter, having the bottom cut off, and attached to the same rubber 
stopper which supports the funnel holding the Gooch crucible. The space between 
the bottle, the crucible, and the supporting funnel is packed with the ice and salt 
mixture. The Gooch crucible is then removed, the outside wiped clean, placed on a 
tared glass and dried in an oven at 80*' C. until the last traces of ether and alcohol 

»"The Modern Asphalt Pavement," by Clifford Richaiidson, 2nd Edition, 558, 1908; "Unter- 
suchung der Kohlenwasserstoffole und Fette," by D. Holde, Berlin, 45, 1913; "Laboratory Manual 
of Bituminous Materials," by Pr6vost Hubbard, N. Y., 100,. 1916. . 



CHEMICAL TESTS 537 

are evaporated. The residue is weighed, and the percentage of solid paraflBnes 
calculated in the original 50 g. of substance taken for analysis.^ 

According to Holde (loc. cit.), the refractive index of the solid paraffines will 
indicate whether the original substance was ozokerite or paraffine, or a mixture 
of the two. An alcohoHc extract is tested at 90° C. on the Zeiss butyro-refractom- 
eter. The residue from ozokerite will show a refractive index of 11.5-17.0, 
whereas the solid paraflBnes derived from petroleum, shale, lignite, etc., will test 
between 1.6 and 6.8. 

Test 34. Saturated Hydrocarbons. This method was devised by 
Richardson,^ and serves to distinguish between various asphaltic products, 
including native asphalts, asphaltites and petroleum asphalts. It is 
used for purposes of identification. 

The portion soluble in 88° petroleum naphtha, separated as in Test 23, is brought 
to exactly 100 c.c. either by adding more 88° naphtha or else by evaporation. 
This is then shaken in a 500-c.c. separatory funnel at 77° F. for exadhj 3 minutes, 
with 30 c.c. of a mixture of concentrated sulphuric acid and fuming sulphuric acid, 
having a specific gravity of 1.84 at 77° F. The funnel is allowed to stand quietly 
overnight, whereupon the acid is drawn ofT and the oils unacted upon treated with 
another 30 c.c. of the acid. This time a few hours' standing should effect a sharp 
separation. If the second acid layer is strongly colored, the treatment should be 
repeated a third time. The naphtha solution is washed successively with water, 
a 5 per cent solution of sodium carbonate and finally with water. The solution is 
evaporated to dryness over a steam bath and the residue weighed. This is equal 
to the saturated hydrocarbons present in the portion soluble in 88° petroleum 
naphtha. As a guide in evaporating the last traces of naphtha from the saturated 
hydrocarbons, a blank test should be run on 100 c.c. of the 88° naphtha, whereupon 
the portion unacted upon is mixed with 0.75 g. of a non-asphaltic petroleum residuum 
and evaporated on the steam bath alongside of the sample under test, until the 
former is reduced to exactly its original weight. 

The results are expressed as the percentage of saturated hydrocarbons present 
in the portion soluble in carbon disulphide (Test 21a). This is calculated in the 
following manner: If a represents the percentage soluble in carbon disulphide, 
h the percentage soluble in 88° naphtha and c the percentage of saturated hydro- 
carbons in b; then the saturated hydrocarbons present in the portion soluble in 

6c 
carbon disulphide will equal — XlOO. 

a 

Test 35. Sulphonation Residue. This test expresses the percentage 
of saturated hydrocarbons in the distillate between 315 and 355° C. 
obtained upon subjecting the bituminous substance to the flask method of 

> An alternate method v:6ed with success by the author, corsists in dissolving 10 g. of the 

substance in the smallest amount of benzol, applying heat if necessary, adding 200 c.c. of 88° 

naphtha, filtering through dried fuller's earth and washing with additional 88° naphtha until the 
filtrate is clear. This removes the dark colored asphaltic substances. The filtrate containing the 

paraffine is distilled to a small bulk, evaporated to dryness on the water bath, the residue dis- 
solved in 25 c.c. of ether and 25 c.c. of alcohol, and treated as described above, 

a" The Modern Asphalt Pavement," 2nd Edition, N. Y., 544. 1908, 



538 ASPHALTS AND ALLIED SUBSTANCES 

distillation (Test 20a). It is used to differentiate tars and pitches 
among themselves as well as from mineral waxes, asphalts (native and 
pyrogenous) and asphaltites. The figures for coal-tar pitches have 
already been given on p. 252. The author cites the following addi- 
tional figures: wood-tar pitch per cent, saponifiable fatty-acid 
pitches per cent, unsaponifiable fatty-acid pitches per cent, residual 
asphalt from Mexican asphaltic petroleum 86 per cent, wurtzilite 
asphalt 87 per cent and gilsonite 85 per cent. 

The method of determining the sulphonation residue as proposed by Dean & 
Bateman,^ consists in distilling sufficient of the material under examination by the 
flask method (Test 20a) to obtain at least 10 c.c. of distillate between 315 and 
355° C. Exactly 10 c.c. of this fraction are measured into a Babcock milk bottle, 
and 40 c.c. of 37 normal sulphuric acid added, 10 c.c. at a time. The bottle and 
its contents are shaken for 2 minutes after each addition, and when all the acid 
has been added, the bottle is kept at a constant temperature of 98-100° C. for 
one hour, during which it is shaken vigorously every 10 minutes. At the end of 
the hour, the bottle is removed, cooled, filled to the top of the graduations with 
ordinary sulphuric acid, and whirled for 5 minutes in a Babcock separator. The 
unsulphonated residue multiplied by 2 gives the per cent by volume directly (each 
graduation being equal to g^Jo of a c.c). 

It is important that the acid should be of the proper strength. A mixture of 
fuming sulphuric acid and ordinary concentrated sulphuric acid should be pre- 
pared to contain exactly 80.07 per cent of SO 3, which constitutes 37 normal acid. 
If the sulphonation residue is dark in color, it should be treated with an excess of 
a 10 per cent sodium hydroxide solution, and if soluble in this reagent, the test is 
regarded as negative. 

The " dimethyl sulphate test "2 was originally proposed for this purpose, but 
has been since disregarded on account of its unreliability. 

Test 36o Mineral Matter. Under this heading we will consider 
in detail the examination of the mineral matter, including the portion 
present in the uncombined state; the portion combined with non- 
mineral constituents; a qualitative or quantitative chemical analysis; 
also microscopic and granularmetric analyses. The distribution of the 
mineral matter, its chemical analysis and microscopic examination are 
of value for purposes of identification. Its granularmetric and in some 
cases its chemical analysis serve as an indication of its adaptability 

'^"The Analysis and Grading of Creosotes," Forest Service Circular 112, Wash., D. C; "Modi- 
fication of the Sulphonation Test for Creosote," Forest Service Circular 191, Wash., D. C; 
"Methods for Testing Coal Tar and Refined Tars, Oils and Pitches Derived Therefrom," by S. R. 
Church, J. Ind. Eng. Chem., 3, 233, 1911; 6, 196, 1913; "Paraffin Bodies in Coal Tar Creosote 
and their Bearing on Specifications," by S. R. Church and J. M. Weiss, J. Ind. Eng. Chem., 6, 
396, 1914. 

""Methods of Asphalt Examination," by Albert Sommer, J. Ind. Eng. Chem., 2, 181, 1910; 
"Application of the Dimethyl Sulphate Test for Determining Small Amounts of Petroleum or 
Asphalt Products in Tars," by C. S. Reeve and R, H. Lewis, Congress of Applied Cberoistry, 
26, 727, 1912; /. Ind, Chem,, 6, 293, 1913. 



CHEMICAL TESTS 530 

for a given purpose, particularly where it is desired to determine the 
resistance to acids or alkalies, etc. The percentage and distribution 
of the mineral matter and its granularmetric analysis are used for 
gauging the uniformity of supply. The percentage of mineral matter 
present, and its granularmetric analysis serve as a criterion of the quality 
for paving purposes. 

Test 36a. Uncombined Mineral Matter. This includes the non-mineral matter 
insoluble in carbon disulphide, and corresponds to the results obtained by Test 216 
(p. 526). Any uncombined mineral matter, or colloidal particles fine enough to 
pass through an asbestos filter would not be included in this determination. 

Test 37b. Mineral Matter Combined with Non-Mineral Constituents. This is 
ascertained by evaporating the carbon disulphide extract of the bituminous aggre- 
gate (Test 21a), burning the residue and ascertaining the weight of the ash thus 
obtained. It will include: (1) the mineral constituents chemically combined with 
the bituminous matter; (2) colloidal mineral constituents which pass through an 
asbestos filter. 

The appearance of the ash on ignition will indicate which of these two classes 
is present. If the ash appears as a gossamer-Jike froth, it will indicate that the 
mineral matter is chemically combined with the bituminous constituents. If the ash 
forms a fine powder, it is an indication that it exists in the form of colloidal particles. 

Test 36c. Chemical Analysis of Mineral Matter. This may include a qualita- 
tive or a quantitative analysis, by any of the methods ordinarily used for this 
purpose. If a quantitative analysis is to be made, the reader is referred to the 
following sources, viz.: 

Mineral Constituents Naturally Present and Added Fillers: " Tentative Methods 
for Ultimate Chemical Analysis of Refractory Materials," Serial Designation: C 18- 
17 T), Proc. Am. Soc. Testing Materials, 17, Part I, 671, 1917; " Standard Specifica- 
tions and Tests for Portland Cement " (Serial Designation: C 9-17), A. S. T. M. 
Standards, Adopted 1916, 432. 

Added White Pigments. " Standard Methods for Routine Analysis of White 
Pigments," A. S. T. M. Standards, Adopted in 1917, 18. 

Added Yellow, Red or Brown Pigments. " Tentative Methods for Routine Analy- 
sis of Yellow, Orange, Red and Brown Pigments Containing Iron and Manganese," 
(Serial Designation: D 50-17 T), Proc. Am. Soc. Testing Materials, 17, Part I, 802, 
1917. 

Test 36d. Microscopic Examination. This is performed by examining a small 
quantity of the mineral matter on a microscope shde under a magnification of 100 
diameters. The method is adapted only to fiinely divided mineral matter, and in 
many cases serves to identify the various forms, such as infusorial earth, clay, silica, 
etc. This test will also give an idea as to the relative fineness of the particles. 

Test 36e. Granularmetric Analysis. The methods which follow have been 
standardized by the American Society for Testing Materials ^ for mineral aggregates 

i" Standard Method for Making a Mechanical Analysis of Sand or Other Fine Highway Material, 
Except for Fine Aggregates Used in Cement Concrete" (Serial Designation: D 7-16); "Standard 
Method for Making a Mechanical Analysis of Broken Stone or Broken Slag, Except tcr Argrt'gates 
Used in Cement Concrete " (Serial Designation: D 18-16); "Standard Method foi Making a Mechani- 
cal Analysis of Mixtures of Sand or Other Fine Material with Broken Stone or Broken Slag, Except 
for Aggregates Used in Cement Concrete" (Serial Designation: D 19-16), A. S. T. M. Standards, 
Adopted in 1916, 535, 537 and 538. 



540 



ASPHALTS AND ALLIED SUBSTANCES 



used in connection with highways. The following three methods have been 
adopted : 

For Sand or Other Fine Highway Material. The method consists of: (1) drying 
at not over 230° F. to a constant weight a sample weighing 50 g.; (2) passing the 
sample through each of the following mesh sieves. 



Meshes Per 


Diameter of Wire. 


Linear Inch 






(2.54 cm.). 


In. 


Mm. 


200 


0.00235 


0.05969 


100 


0.0045 


0.1143 


80 


0.00575 


0.1460 


50 


0.009 


0.22865 


40 


0.01025 


0.26035 


30 


0.01375 


0.34925 


20 


0.0165 


0.4191 


10 


0.027 


0.6858 



The order in which the sieves are to be used in the process of sifting is imma- 
terial and shall be left optional; but in reporting results, the order in which the 
sieves have been used shall be stated; (3) determining the percentage by weight 
retained on each sieve, the sifting being continued until less than 1 per cent of the 
weight retained shall pass through the sieve during the last minute of sifting; and 
(4) recording the mechanical analysis in the following manner: 

Passing 200-me8h sieve % 

Passing 100-mesh sieve and retained on a 200-mesh sieve % 

Passing 80-mesh sieve and retained on a lOO-mesh sieve % 

Passing 50-mesh sieve and retained on a 80-mesh sieve % 

. . • • % 

Total 100.00% 

For Broken Stone or Broken Slag. The method shall consist of: (1) drying at 
not over 230° F. to a constant weight a sample weighing in pounds 6 times the 
diameter in inches of the largest holes required; (2) passing the sample through 
such of the following size screens having circular openings as are required or called 
for by the specifications, screens to be used in the order named: 3|, 3, 2|, 2, 1^, 
I4, 1, h h and \ in.; (3) determining the percentage by weight retained on each 
screen; and (4) recording the mechanical analysis in the following manner: 

Passing i-in. screen % 

Passing 5-in. screen and retained on a j-in. screen % 

Passing |-in. screen and retained on a 2 -in. screen % 

Passing 1-in. screen and retained on a f-in. screen % 

% 

Total 100 . 00% 

For Sand or Other Fine Material with Broken Stone or Broken Slag. The method 
shall consist of: (1) drying at not over 230° F. to a constant weight, a sample 
weighing in pounds 6 times the diameter in inches of the largest holes required; 
(2) separating the sample by the use of a screen having circular openings j in. 
in diameter ; (3) examining the portion retained on the screen in accordance 
with the method for broken stone or broken slag; (4) examining the portion passing 
the screen in accordance with the method for sand or other fine highway material; 
and (5) recording the mechanical analysis in the following manner: 



CHEMICAL TESTS 



541 



Passing 200-mep'i sieve 

Passing 100-mesh sieve and retained on a 200-niesh sieve. 
Passing SO-mesh sieve and retained on a 100-mesh sieve . 



Passing 10-mesh sieve and retained on a 20-mesh sieve 

Passing i-in. screen and retained on a 10-mesh sieve. . 

Passing l-in. screen and retained on a j-in. screen. . . . 

Passing J-in. screen and retained on a 2-in. screen. . . . 



Total , 



100.00% 



Elutriation Test for Sand or Fine 
Filler. This test is adapted to fine 
mineral particles passing a 200-mesh 
sieve. Place 5 g. in a beaker about 
120 mm. high, holding 600 c.c, and 
fill almost to the top with distilled 
water at exactly 70° F. Agitate 
with compressed air until the min- 
eral particles are brought into 
suspension, and in such a manner 
that no whirHng results. Stop the 
blast and allow the liquid to stand 
exactly 20 seconds, whereupon the 
water above the sediment is im- 
mediately decanted through a 200- 
mesh sieve without, however, pour- 
ing off any of the sediment. The 
operations of agitation, sedimenta- 
tion, and decantation are repeated 
with fresh water three times. The 
particles caught on the 200-mesh 
sieve are washed back into the 
sample remaining in the beaker, 
which is dried to constant weight 
and weighed. The difference repre- 
sents the amount removed by 
elutriation, which should be ex- 
pressed in percentage. 1 

Test 36f. Specific Gravity of 
Mineral Matter. Two methods 
are recommended, depending upon 
whether the particles are finer or 
coarser than 1 in. in diameter. 

For Aggregates Whose Particles 
are Less than j In. The U. S. 
Bureau of Standards' Modifica- 
tion of Le Chatelier's flask is 

1" Standard Forms for Specifications, 
Tests, Reports and Methods of Sampling 
for Road Materials," Bulletin No. 555, 
U. S. Dept. Agriculture, Wash., D. C, p. 
32, Nov. 26, 1917. 



Ground Glass 
Stopper- 



Have two 0.1 cc 
Graduations extend 
above } and 

below Mark- 




^ 

]at20% _V^ 




K 
/< 9 cm - ->j 

From A. S. T. M. Standards. 

Fig. 191. — Bureau of Standards' Modification of 
Le Chatelier's Specific Gravity Flask. 



542 



ASPHALTS AND ALLIED SUBSTANCES 



'2IGalvanized 












S 


,... 






Note:N 
/otvere 
topreve 


otch is fi/ed across 
ndofspouf ^rii' CZV 






" 




ntdrip.=:,-l^^-^ 


; 


r 
7 




i 'brass pipe. £i 'long' 






eooce 

beaker 


7 


» 


















V 


Three lu 
bottom . 


IS soldered on 
Ymmetrically 


) 





used^ as illustrated in Fig. 191. It is first filled with kerosene to a point on the 
stem between and 1 c.c, and 57 g. of the aggregate at the same temperature as 
the hquid slowly introduced, and freed from air by rolling the flask in an inchned 
position. After all the aggregate has been introduced, the level of the hquid will 
rise to some division on the graduated neck, the difference between the readings 
being equal to the volume displaced. The flask during the operation shall be im- 
mersed in water at a definite temperature. The specific gravity at this temperature 
is equal to the weight of the aggregate in grams divided by the volume displaced 
in cubic centimeters. 

For Aggregates Composed of Fragments Larger than I In. The Goldbeck appara- 
tus ^ illustrated in Fig. 192 is used for 
this purpose; 1000 g. of aggregate are 
dried to constant weight, weighed to the 
nearest 0.5 g., and immersed in water for 
24 hours. The pieces are then individually 
surface-dried with a towel, the sample 
reweighed and immediately introduced 
into the cylinder, which has previously 
been filled to overflowing with water at 
77° F. The displaced water is caught in a 
tared beaker, and weighed. If the weight 
of the dry aggregate in air is a, and 
the weight of the displaced water 6, then 
the apparent specific gravity is equal to 
a divided by h. The difference between 
the original weight of the specimen and 
its weight after 24 hours' immersion is 
used to determine the percentage of ab- 
sorption. If c equals the weight of the water absorbed by the dry specimen in 24 
hours, then the true specific gravity at 77° F. is equal to a divided by (b—c). 

Test 37. Saponifiable Constituents. Under this heading will be 
included tests applicable to oils, fats and resins, including the acid value, 
lactone value, ester value, and saponification value, also the separation 
of fatty and resin acids. These tests are adapted to certain bituminous 
substances for purposes of identification, also for gauging the uniform- 
ity of supply. They are especially suitable for examining: montan 
wax, wood tar and wood-tar pitch, rosin pitch and fatty-acid pitch, 
and to determine the quality of the last named. 

The relation between the acid, lactone, ester and saponification 
values, also the unsaponifiable and saponifiable constituents is shown 
in the following table: 

1 Circular No. 33, Bureau of Standards, p. 27; " Standard Specifications and Tests for Portland 
Cement" (Serial Designation: C. 9-17), A. 5. T. M. Standards, Adopted in 1916, 436. "Specific 
Gravity of Non-Homogeneous Aggregates," by Provost Hubbard and F. H Jackson, Jr., Proc. Am. 
Soc. Testing Materials, 16, Part II. 380, 1916. 

2 "Standard Forms for Specifications, Tests, Reports and Methods of Sampling for Road Materials," 
Bull. No. 55.5, U. S. Eept. of Agriculture, Wash., D. C, p. 31, Nov. 26, 1917. 



Fig. 192. — Goldbeck's Specific Gravity 
Apparatus. 



CHExMICAL TESTS 



543 



Saponification Value 

(Saponifiable Matter) 


Acid Value 


Free Fatty Acids 


Free Resin Acids 


Lactone Value 


Anhydrides and Lactones 


Ester Value 


'Neutral Fats 


[Glycerol] 


Fatty Acids 




Waxes 


Fatty Acids 


Unsaponifiable Matter 


Higher Alcohols 


Free Higher Alcohols 






Hydrocarbons 



The saponification and acid values have been used for distinguish- 
ing between native and petroleum asphalts (p. 298), in accordance 
with the method proposed by J. Marcusson (see p. 545). ^ 

Test 37a. Free Acids (" Acid Value "). Boil 5.00 g. of the material with 50 
c.c. of carefully neutralized 95 per cent ethyl alcohol for 20 minutes.^ The liquid 
is decanted from the insoluble residue while hot, the latter boiled with another 50 
c.c. of alcohol, and the processs repeated, until the extract no longer reacts acid with 
alkah blue 6-B (or phenolphthalein). The residue is then disregarded. To the 
combined extracts, add 10 c.c. of a 25 per cent barium chloride solution and 6 
drops of a 3 per cent alcohoHc solution of elkcli 1 lue 6-B (cr an equivalent amount 
of 1 per cent alcohohc phenolphthalein), and titrate cold with standard N/10 
caustic potash. 3 As the free acids are neutrahzed by the alkah, the barium soaps 
are precipitated, and at the same time the unsaponified substances are thrown 
out by the water contained in the N/10 caustic potash, until at the close of the 
titration the solution becomes almost clear, rendering the end-point sharp. The 
acid value is equivalent to the number of milligrams of potassium hydroxide 
required to neutralize the free fatty acids in 1 g. of the substance. • 

Test 37b. Lactones and Anhydrides (" Lactone Value ")• These are determined 
as follows: (1) Find the acid value (Test 37a), and the ester value (Test 37c) of the 
original substance. (2) Find the acid value (Test 37a) and the ester value (Test 
37c) of a weighed quantity of the free acids liberated from the substance after 
saponification (Test 39). If acid and ester values (1) are equal to respective acid 
and ester values (2); then lactones only are present. If acid value (1) is less than 
acid value (2), and ester value (2) is equal to 0; then glycerides only are present. 
If acid value (1) is less than acid value (2), and ester value (1) is greater than 
ester value (2); then both glycerides and lactones are present. 

The true ester value is equal to ester value (1) minus ester value (2); and the 
true lactone value is equal to ester value (2). 

»Z. anoew. Chem., 24, 1297, 1901. 

2 Bituminous materials with high fueing-points should be fluxed to semi-liquid coneistency with a 
given weight of neutral paraffine oil. 

3 Prepared by dissolving 5.612 g. pure caustic potash in 500 c.c. 95 per cent alcohol, diluting to 
exactly 1 litre with water at 60° F. and carefully standardizing against sulphuric acid of known etrength. 



544 ASPHALTS AND ALLIED SUBSTANCES 

The foregoing results may be checked by finding the acid values of the original 
substance and the liberated acids. The true ester value equals the acid value of the 
free acids minus the acid value of the original material. Similarly, the lactone 
value is equal to the saponification value minus the sum of the acid and ester 
values. 

Test 37c. Neutral Fats (" Ester Value ")• The ester value corresponds to the 
number of milligrams of potassium hydroxide consumed in saponifying esters 
(neutral fats, otherwise known as triglycerides). If lactones or anhydrides are 
absent, the ester value may be calculated by subtracting the acid value from the 
saponification value. If lactones and anhydrides are present, then the ester 
value may be calculated by subtracting the sum of the acid and lactone values from 
the saponification value. 

Test 37d. Saponification Value. The saponification value represents the num- 
ber of milligrams of potassium hydroxide consumed in the complete saponification 
of 1 g. of the substance. It represents the sum of the acid, lactone and ester 
values, and is ascertained in the following manner: 

Prepare a 5 per cent solution of caustic potash dissolved in equal volumes of 
95 per cent ethyl alcohol and 90 per cent thiophene-free benzol, and standardize 
against sulphuric acid of known strength.^ Saponify 5 g. of the substance with 
50 c.c. of this solution by boiling under a reflux condenser | to 1 hour, depending 
upon the rapidity with which the substance goes into solution. Evaporate the 
benzol on a water bath, add 100 c.c. water, boil, decant from the residue, add 50 
c.c. more water, })oil, decant and repeat until all the alkali has been removed 
(tested by adding a drop of phenolphthalein). Combine the extracts, add 20 c.c. 
of 25 per cent barium chloride solution (BaCU -21120), and 3 c.c. each of a 1 per 
cent alcoholic phenolphthalein solution and a 3 per cent alcoholic solution of alkali 
blue 6-B.2 Titrate the warm solution with N. sulphuric acid. As the barium hydrox- 
ide becomes neutralized, a copious precipitate of barium sulphate forms which 
renders the end-point distinct. When the color changes, boil, and if necessary 
run in more sulphuric acid until the color remains green on boiling. Calculate the 
quantity of caustic potash required for saponification. 

Test 37e. Estimation of Fatty and Resin Acids. If both fatty and resin acids 
are present in the mixture, it is not a simple matter to separate them quantita- 
tively. The method of procedure consists in first saponifying a grams of the 
substance, sufficient to yield about 5 g. of the mixed acids, and separating the 
saponifiable matter as described in Test 39. The fatty acids are then separated 
from the resin acids by the Twitchell-Gladdiug process as follows: 

Dissolve the mixed acids in 50 c.c. absolute alcohol adding any insoluble matter 
to the separated resin acids subsequently obtained. Cool to 10° C, pass in a 
stream of dry hydrochloric acid gas for 1 to 2 hours, let stand ^ hour at room 
temperature, dilute with five volumes of water, boil for 15 minutes under a reflux 
condenser, cool, and extract the fatty-acid esters and resin acids with benzol. 
Neutralize the aqueous solution, evaporate to a small bulk, acidify, and again 

1 Approximately 45 c.c. of N. sulphuric acid will be required to neutralize 50 c.c. of the 5 per 
cent caustic potash solution. 

3 Marcusson finds that by using the two Indicators together, the end point of the titration is sharper, 
being evidenced by a change in color from red to green. 



CHEMICAL TESTS 545 

extract with benzol to remove any traces of acids not previously removed. Com- 
bine the extracts, now containing all the fatty-acid esters and resin acids, add 50 
CO. of caustic potash solution (10 g. caustic potash, 10 c.c. ethyl alcohol, and 100 
c.c. water) to saponify the free resin acids, and draw off the aqueous layer together 
with any intermediate layer between the aqueous and benzol layers (containing 
resin soaps difficultly soluble in the alkaline liquor). Exhaust the aqueous soap 
solution with benzol to recover any fatty acid esters. The combined benzol extracts 
are washed in turn with water, twice with 10 c.c. of the potash solution, and 
finally again with water. The benzol solution containing most of the fatty acids 
in the form of esters is evaporated to a small bulk, saponified, the free fatty acids 
liberated with hydrochloric acid, separated and weighed as a check. 

The resinous soap solution is united with the various aqueous and alkaline 
extracts, evaporated to a small bulk, acidified with dilute hydrochloric acid, and 
extracted with ether to remove the free resin acids. These are evaporated to 
dryness at 105° C. and weighed. The residue consists of the resin acids contami- 
nated with more or less fatty acids which failed to become esterfied. Dissolve in 
25 c.c. of 95 per cent alcohol in a 100-c.c. stoppered measuring cylinder, add 2-4 
drops of a 1 per cent alcohoHc solution of alkali blue 6-B, and neutralize with 
aqueous caustic soda solution (1 : 2). Heat on a water bath for 15 minutes, cool, 
dilute to 100-c.c. with ether, agitate, add 1 g. of finely pulverized silver nitrate 
(dry), and continue the agitation for 15 minutes to convert the fatty-acid soaps 
into their corresponding silver salts. Settle overnight, decant 75 c.c. of the clear 
liquid into a separatory funnel, and shake with 20 c.c. dilute hydrochloric acid 
(1 :2). Draw off the ether layer, and extract the aqueous solution with two 20 c.c. 
portions of ether. Combine the ether extracts, wash with 20 c.c. water, filter 
into a tared crucible, evaporate to dryness at 105° C, weigh and add to the 
residue insoluble in alcohol mentioned above. The total residue consists of the 
practically pure resin acids (6 grams). 

46 
Per cent resin acids in original substances = — X 100. Since resins carry an aver- 

3a 

age of 8 per cent unsaponifiable constituents, their percentage may be approximately 

calculated as follows: 

. . • . . , , 1445 
Per cent resm in origmal substance = . 



Test 38. Asphaltic Constituents. The methods which follow 
have been proposed by J. Marcusson ^ for differentiating between 
native and petroleum asphalts (p. 298). They also give an insight 
into the composition of asphalts themselves, and in this respect the 
author regards them of special merit. The value and possibilities 
of these determinations do not appear to be generally appreciated, 
but as time goes on they will certainly be recognized. The figures in 
table on page 546 will illustrate their utility; the results for crude 
Trinidad and refined Hermudez asphalt are reported by Marcusson, the 
balance having been obtained by the author. 

» Z. angew. Chem. 29, 346, 1916. 



546 



ASPHALTS AND ALLIED SUBSTANCES 





Non-mineral 






Residual 


Blown 




Residual 




Constituents 


Refined 


Fluxed 


Asphalt 


Asphalt 


Hard 


Oil from 




of Crude 


Bermudez 


Graham- 


from Mex- 


from 


Sludge 


Mixed- 




Trinidad 


Asphalt. 


ite.* 


ican 


Asphaltic 


Asphalt. 


base 




Asphalt. 






Petroleum. 


Petroleum. 




Petroleum. 


Fusing-point (K. 
















andS. method).. 


132"' F. 


135° F. 


161° F. 


160° F. 


165° F. 


180° F. 


80° F. 


Free asphaltouB 
















acids 


6.4% 


3.5% 


0.90% 


61% 


1.87% 


0.81% 


0.92% 


Asphaltous acid 
















anhydrides 


3.9% 


2.0% 


1.28% 


Trace 


0.25% 


1.61% 


0.46% 


Asphaltenes 


37.0% 


35.3% 


17.28% 


5.81% 


Trace 


27.01% 


Trace 


Asphaltic resins . . . 


23.0% 


14.4% 


30.75% 


26.72% 


16.66% 


25.68% 


25.34% 


Oily constituents. . 


31.0% 


39.6% 


48.50% 


65.45% 


80.57% 


44.09% 


74.59% 



* Composed of 15 per cent grahamite and S5 per cent residual oil derived from asphaltic petroleum. 

Test 38a. Free Asphaltous Acids. Dissolve 5.00 g. of the asphalt in 25 c.c. 
benzol by boiling under a reflux condenser. Add 200 c.c. ethyl alcohol, let 
settle, decant the solution from the pitchy residue, and titrate the former cold 
with N/10 alcohoHc sodium hydroxide, using phenolphthalein as indicator. Dilute 
with an equal volume of water and extract the unsaponifiable constituents by 
shaking with successive portions of benzol until the extract becomes clear. Evap- 
orate the alcohohc soap solution to a small bulk, hberate the asphaltous acids 
by acidifying with hydrochloric acid, extract with benzol, evaporate the extract to 
dryness at 100° C. and weigh. The free asphaltous acids appear as a tar-hke to 
resinous mass, soluble in alcohol, benzol and chloroform, but nearly insoluble 
in 88° petroleum naphtha. When heated to 120° C. they are converted into the 
corresponding anhydrides. 

Test 38b. Asphaltous Acid Anhydrides. In the foregoing test, the unsaponi- 
fied portion is united with the pitchy substances precipitated by alcohol from the 
original benzol solution. These are saponified by boiling under a reflux condenser 
for 1 hour with N-alcohohc caustic potash in the presence of benzol, the solution 
is diluted with an equal volume of water, and the unsaponified constituents extracted 
with successive portions of benzol. The alcoholic soap solution is then evaporated 
to a small bulk, the asphaltous acid anhydrides liberated by acidifying with hydro- 
chloric acid, extracted with benzol, evaporated to dryness at 105° C. and weighed. 
These are very similar in appearance to the free asphaltous acids. On heating to 
high temperatures, they are converted into unsaponifiable products similar in appear- 
ance to the asphaltenes. 

Test 38c. Asphaltenes. After separating the saponifiable constituents according 
to Tests 38a and 38&, the bodies which have not combined with alkali are dissolved 
in the smallest possible quantity of benzol (not exceeding 10 c.c), and the solution 
poured into 200 c.c. of 88° petroleum naphtha. ^ The insoluble matter is filtered 
on a Gooch crucible as described in Test 23, washed with 88° naphtha, dried and 
weighed. This represents the asphaltenes, which appear as a dark brown to black 
powder similar to grahamite in characteristics. On heating it does not melt, but 
swells and decomposes into a compact and hard coke. Asphaltenes are supposed 
to be formed by the addition of oxygen or sulphur to petroleum resins, also to 
inter-molecular changes taking place on heating them in air. They are soluble in 

1 Of which at least 85 per cent by volume should distil between 35 aod 65° C. 



CHEMICAL TESTS 547, 

benzol, chloroform and carbon disulphide, almost completely insoluble in alcohol 
and 88° petroleum naphtha, and sparingly soluble in ether and acetone. They are 
characterized by a high percentage of sulphur (7-13 per cent) and under the 
influence of light are converted into an insoluble modification (p. 574). The 
asphaltenes and their parent substances, the asphaltic resins, are regarded as 
saturated polycychc compounds containing sulphur or oxygen, either of which 
can replace the other. 

Test 38d. Asphaltic Resins. The solution of 88° petroleum naphtha obtained 
from Test 38c is evaporated to about 25 c.c, distributed over 25 g. fuller's earth 
in a paper thimble, and extracted hot in a Soxhlet with 88° petroleum naphtha. 
If the first extract is dark colored, it is concentrated to about 25 c.c, poured over 
more fuller's earth, and the process repeated. The extract should have a straw 
or hght yellow color. The asphaltic resins are retained by the fuller's earth, from 
which they may be extracted by carbon disulphide, evaporated to dryness at 100° C, 
and weighed. These form the first stage in the conversion of petroleum hydro- 
carbons into asphaltenes, and consist of sohd, reddish-brown to brownish-black 
substances fusing below 100° C, completely soluble in 88° naphtha, chloroform, 
carbon disulphide, benzol, but only sparingly soluble in hot or cold acetone. After 
absorption by fuller's earth they become insoluble in 88° petroleum naphtha. The 
asphaltic resins are formed by heating the oily constituents for some time to 120° 
C . accompanied by a darkening in color and absorption of atmospheric oxygen. 

Test 38e. Oily Constituents. The 88° petroleum naphtha extract from the 
fuller's earth in Test 3Sd, is distilled to a small bulk, and evaporated to dryness 
at 100° C. until the odor of petroleum naphtha is no longer apparent. The oily 
constituents remaining as residue are weighed. These appear as a viscous oil, 
and constitute the most inert bodies contained in asphalts. As a general rule, the 
softer the asphalt, the larger will be the percentage of oily constituents. Marcusson 
reports that Trinidad petroleum contains 42 per cent of oily constituents, Trinidad 
asphalt 17 to 19 per cent (figured on the crude dry substance containing the mineral 
ingredients) and grahamite 2 to 3 per cent. 

Test 39. Estimation of Unsaponfiable and Saponifiable Matters, 

In the case of bituminous materials, the estimation of the unsaponifi- 
able and saponifiable matters is of value for purposes of identification. 
Certain bituminous substances, such as montan wax, rosin pitch, and 
fatty-acid pitch are often composed largely of saponifiable constitu- 
ents. Others, including pine tar, pine-tar pitch, hardwood tar, hard- 
wood-tar pitch, peat tar, lignite tar, bone tar, bone-tar pitch and 
other forms of fatty-acid pitches contain smaller percentages. This 
test is also used for gauging the uniformity of supply, and in the 
case of fatty-acid pitches, as a criterion of the quality. 

The following procedure has been devised by the author for specifically examin- 
ing bituminous materials or admixtures of bituminous materials with animal or 
vegetable oils and fats, since the customary methods do not adapt themselves 
especially well, due to the formation of troublesome emulsions. The bituminous 
material is first freed from insoluble constituents, including any mineral matter, 
by boiling with benzol under & xeflux condenser, cooling and filtering through Sk 



548 



ASPHALTS AND ALLIED SUBSTANCES 



Gooch crucible, following the precautions described in Test 21a. The insoluble 
constituents are dried at 100° C, and weighed. Sufficient of the bituminous sub- 
stance should be taken to yield approximately 5.0 g. of extract. "The benzol solu- 
tion is evaporated or distilled to 50 c.c, and 50 c.c. of the saponifying liquid added 
from a pipette. This should consist of a 10 per cent solution of caustic potash, 
prepared by dissolving 100 g. of anhydrous potash in 500 c.c. of 95 per cent ethyl 
alcohol, and diluting to a litre with 90 per cent benzol. The liquid is allowed to 
stand overnight to permit any carbonate to settle, and the clear solution decanted. 
After the saponifying agent is added, the mixture is boiled under a reflux condenser, 
for ^-1 hour, and the contents of the flask while still warm poured in a separatory 
funnel containing 150 c.c. of boiling water and 25 c.c. of a 10 per cent solution of 
potassium chloride. Add 250 c.c. of benzol, agitate vigorously, and allow the fun- 
nel to rest quietly in a warm place until the solvent separates. If an emulsion 
forms which refuses to separate on standing, add 200 c.c. more benzol and 100 c.c. 
95 per cent ethyl alcohol and stand in a warm place overnight. This will invari- 
ably effect a more or less complete separation of the solvent. From this point on 
the method is illustrated by the following tabular outline: 

Saponify as described: 

Draw off the eoap solution as completely as possible. 

Decant the benzol layer, leaving the intermediate layer in the eeparatory funnel. 



Aqueous Soap Solution. 
Exhaust with 200 c.c. of portions of benzol. 



Aqueous Soap 
Solution. 



Combined Benzol 
Extracts. 



Benzol Layer. 



Combine and exhaust with 100 c.c. portions of 
50% alcohol. 



Benzol Solution. 



Combined Alcoholic 
Extracts. 



Intermediate Layer. 



Combine and exhaust with benzol. 



Combined Benzol 
Extracts. 



Combine, evaporate to a small bulk, complete the 
evaporation at 100° C, cool and weigh the 

Vnsaponifiable Constituents. 



Alcoholic Soap Solution. 



■ Combine - 



Transpose with dilute hydrochloric acid, warm and exhaust with benzol. Separate the aqueous 
solution containing the glycerol and mineral salts. Evaporate the combined benzol extracts to a small 
bulk, and then complete the evaporation of solvent at 100° C. Cool and weigh. Weight equals the 
free acids derived from the saponifiable constituents. 



In the case of bituminous materials that are more or less completely saponifiable, 
the intermediate layer is apt to be absent. In this case the process will simplify 
itself considerably. The foregoing procedure will separate the unsaponifiable consti- 
tuents in practically an ash-free state. 

Test 39a. Hydrocarbons. Boil 2 g. of the unsaponifiable matter with 4 c.c. of 
acetic anhydride under a reflux condenser for 1 hour. Add 25 e.g. of 95 per cent 



CHEMICAL TESTS 549 

ethyl alcohol, heat to boiling, decani through an asbestos Gooch crucible, and 
remove all traces of acetic anhydride by washing with successive portions of warm 
alcohol. Dry the residue on the Gooch at 100° C. Its weight is equal to the 
hydrocarbons present. 

Test 39b. Higher Alcohols (" Cholesterol "). The filtrate from the foregoing 
(Test 39a) is evaporated to dryness, then dissolved in the smallest possible quantity 
of hot absolute ethyl alcohol and allowed to cool. The cholesterol and phytosteryl 
(sometimes termed sitosteryl) will crystallize as acetates. Filter and wash with 
95 per cent alcohol. Find the melting-point by the capillary tube method as 
ordinarily used for pure organic substances. Cholesterol acetate will melt between 
114.3 and 114.8° C, whereas phytosteryl acetate will melt above 125° C. Re- 
crystalhze several times from hot absolute alcohol and redetermine the melting-point. 
If the fifth to seventh crop of crystals tests below 115-116° C, then phytosteryl is absent. 

Cholesterol may also be detected by boiling 1 g. of the substance with 2 c.c. of 
chloroform and 20 drops of acetic anhydride. The solution is allowed to cool 
and the clear liquid decanted into a porcelain crucible. Then 1 drop of con- 
centrated sulphuric acid is added to the liquid. If cholesterol is present, a violet- 
pink to reddish coloration will be obtained. (For the behavior of resin acids in the 
foregoing test, see Test 43.) 

Cholesterol indicates the presence of animal oils, fats or waxes (such as wool 
grease), whereas phytosteryl indicates vegetable oils, fats or waxes. This test is 
therefore of value in detecting which class of substances is present in admixture 
with bituminous material. 

Test 40. Glycerol. Glycerol indicates the presence of animal and 
vegetable oils or fats (triglycerides). Certain fatty-acid pitches also 
contain a small percentage of glycerol (see p. 331). This test is of 
special importance in the examination of bituminous paints, cements, 
varnishes and japans (p. 572.) 

Saponify 5-10 g. of the substance under examination, weighing exactly, and 
using 25 c.c. of the saponifying agents described in Test 39. Extract the unsaponi- 
fiable constituents with benzol as described, and then transpose the soap solution 
with a slight excess of dilute sulphuric acid (instead of using hydrochloric acid). 
Warm the liquid and extract the fatty acids with benzol. 

Evaporate the aqueous solution to a small bulk, and make slightly alkaline 
with dilute caustic soda. Cool, dilute to about 100 c.c. and determine glycerol 
by any of the standard methods proposed for this purpose.^ 

Test 41. Diazo Reaction. This test is used for identifying bituminous 
substances carrying phenols, including wood tar and wood-tar pitch, 
oil-gas- and water-gas-tars and pitches, shale tar, peat- and lignite- 
tars and pitches, bone tar, bone-tar pitch and the various coal- 
tar pitches. 

; This reaction was devised by E. Graefe.^ It is carried out by boiling 2 g. of 

i;, 1 "Aids in the Commercial Analysis of Oils, Fats, etc.," by G. F. Pickering, London, 1917; " Analy- 
iaiB of Crude Glycerin," by the International Standard Methods, J. Soc. Chem. Ind., 30, 556, 1911 . 

2 " Distinction between Lignite Pitch and other Pitches," Chem. Zeit., SO, 298, 1906; Marcusaon 
and Eickmann, Chem.-Zeit., 32, 965, 1908. 



550 ASPHALTS AND ALLIED SUBSTANCES 

the bituminous substance with 20 c.c. N. aqueous caustic soda, for approximately 
5 minutes. After coohng, the Hquid is filtered. If the filtrate is dark colored, 
it may be hghtened by adding finely pulverized "salt." It is then cooled in ice, 
and a few drops of freshly prepared diazobenzolchloride solution (prepared by 
treating anilin with hydrochloric acid and sodium nitrite) added. If phenols are 
present a red coloration will result, sometimes accompanied by a reddish precipitate. 

Assuming that the bituminous substance gives the diazo reaction, the question 
will often arise whether the product is a straight-distilled pitch, or an asphalt 
" cut-back " with a high boiling-point distillate containing phenolic bodies, derived 
from coal tar, lignite tar, etc. Marcusson has worked out a method applicable 
under these circumstances,^ which consists in dissolving 10 g. of the bituminous 
substance in 15 c.c. of benzol, and pouring the solution into 200 c.c. of 88° petroleum 
naphtha. The resulting precipitate is washed with petroleum naphtha and dried. It 
is then boiled for 15 minutes with N/2 alcohoHc caustic potash under a reflux 
condenser to extract the phenols. The Hquid is cooled and filtered, the alcohol 
evaporated, and the residue dissolved in water. Sodium chloride is added to clarify 
the Hquid and remove any substances imparting a dark color, the solution is 
filtered and the filtrate treated for the diazo test described above. If a straight 
distilled pitch containing phenols is present, a positive reaction will be obtained. If 
the original substance gives the diazo test, but the residue treated in the above 
way does not, then the admixture of high boiling-point oils containing phenolic 
bodies with a substance free from phenols (e.g. asphalts, etc.) is established. It 
is claimed that the presence of 10 per cent asphaltic substances may be detected 
in this manner. 

Where bituminous substances contain calcium carbonate, the phenoHc bodies 
present combine with the lime, forming insoluble calcium phenolate which yields 
but a faint diazo reaction. However, on treating such substances with a solvent 
in the presence of hydrochloric acid, the calcium phenolate is decomposed, and the 
diazo reaction becomes much more delicate. 

Test 42. Anthraquinone Reaction. The anthraquinone reaction 
is used for detecting anthracene in tar products produced at high 
temperatures, including oil-gas-tar and pitch, water-gas-tar and pitch, 
and the various coal-tar pitches. This test is therefore valuable for 
purposes of identification. 

The tar or pitch is first subjected to distillation in accordance with the retort 
method (Test 206), the offtake and condensing tube being kept warm to prevent 
the accumumulation of any solid distillate. The distillate passing over between 
270 and 355° C. is caught separately and examined for anthracene in the following 
manner. The fraction is heated until it is thoroughly fluid to secure a uniform 
sample, and 5 g. weighed out, while hot. After cooHng, 10 c.c. of absolute ethyl 
alcohol are added, the solids allowed to crystallize and the liquid decanted. The 
solid substances containing the anthracene are dried on a water bath, transferred 
to a 500-c,c. flask connected with a return condenser, 45 c.c. of glacial acetic acid 
added, and the contents boiled for 2 hours. The following mixture is then added 
drop by drop through a separatory funnel, viz.: 15 g. of anhydrous chromic acid 
dissolved in 10 o.c. of glacial acetic acid, and 10 c.c. of water. The boiling is 

1 Chem. Rev. Fett-und Harx-Ind., 18, 47. 1911. 



CHEMICAL TESTS 551 

continued for another 2 hours, the flask cooled, and 400 c.c. cold water added. 
This treatment oxidizes the anthracene to anthraquinone, which on cooling separates 
as a solid mass. This is filtered, washed with hot water, then with a hot 1 per 
cent solution of caustic soda and again with hot water. The residue of anthra- 
quinone is then dried and its weight multiplied by 0.856 to obtain the corresponding 
weight of anthracene. From 0.25 to 0.75 per cent of anthracene is found in coal 
tars, and a corresponding larger percentage in coal-tar pitches. 

A color reaction for establishing the presence of anthracene consists in boiling 
the crystals of anthraquinone with zinc dust and caustic soda solution, whereupon 
an intense red colored solution is obtained, which on filtering in contact with air 
becomes decolorized. 

Test 43. Liebermann-Storch Reaction. This is a rapid qualitative 
test for detecting the presence of rosin, rosin oil, or cholesterol. One 
gram of the substance is dissolved in 3 c.c. of acetic anhydride at a 
gentle heat, cooled and the clear liquid decanted into a porcelain cru- 
cible. Add 1 or 2 drops of sulphuric acid sp.gr. 1.53 (containing 62.53 
per cent of pure sulphuric acid, prepared by diluting 34.7 c.c. of concen- 
trated sulphuric acid with 35.7 c.c. of water). Rosin and rosin oil 
will produce a fugitive violet coloration turning to a brown, whereas 
cholesterol will produce a fugitive rose color turning rapidly to a 
dark green. If rosin or rosin oil is present in conjunction with 
cholesterol, the test becomes valueless. 

Fossil resins (copals, etc.) also fatty-acid pitches give a permanent brown color 
and do not interfere with the foregoing test. Linseed, cotton-seed, china-wood and 
corn oils give a permanent greenish-brown coloration, whereas palm oil, bone tar, 
and crude olein give a permanent brownish-yellow coloration. 



CHAPTER XXXII 

METHODS OF TESTING MANUFACTURED PRODUCTS 

This chapter will include methods for analyzing and testing 
manufactured products, containing in addition to bituminous sub- 
stances, materials of a non-bituminous character, such as mineral 
aggregates, mineral, animal or vegetable fibres, fabrics, water in the 
form of emulsion, volatile solvents, animal and vegetable fats or oils, 
colored pigments, etc. The tests about to be described will accord- 
ingly supplement those embodied in Chapters XXVIII to XXXI 
inclusive, which were restricted to examining crude, refined or blended 
bituminous substances, without other additions. 

BITUMINIZED MINERAL AGGREGATES 

Products falling into this class include native and artificial mixtures 
of bituminous matter with mineral aggregates, viz: bituminous macadam 
pavements, bituminous concrete pavements, sheet asphalt pavements, 
asphalt block pavements, asphalt mastic floorings, bituminous expansion 
joints (containing mineral matter but not felt), pipe-sealing compounds, 
moulding compositions and products used for electrical insulation. 

Effect of Moisture. Various methods have been suggested from time to time 
for ascertaining the water absorption of paving materials.^ It is recognized that all 
pavements absorb more or less moisture, but no standard method has been pro- 
posed for this purpose. Richardson suggests the use of cylinders of the same 
dimensions as used for the impact test (p. 555) namely 1.25 in. in diameter, by 
1 in. high, having the greatest possible density, which in the case of surface mix- 
tures for sheet asphalt pavements, will weigh about 50 g. They are immersed :n 
water for 3 months, and the gain in weight noted at various intermediate periods. 
This same method will adapt itself for testing asphalt block pavements and asphalt 
mastic floorings. 

The following tentative methods have been proposed for testing the water 
absorption of moulded insulating materials. 2 One-half of the standard briquette 

» Whipple & Jackson, Eng. News, 47, 1900; "The Testing of Bitumens for Paving Purposes," by 
A. W. Dow, Proc. Am. Soc. Testing Materials, 3, 368, 1903; Eng. News, 61, 520, 1904; "The Modern 
Asphalt Pavement," 2nd Edition, Chapter XXIV, 461. 

2 "Tentative Tests for Molded Insulating Materials" (Serial Designation: D 48-17 T), Proc. Am. 
Soc. Testing Materials, Part I, 790, 1917, 

552 



METHODS OF TESTING MANUFACTURED PRODUCTS 



553 



used for ascertaining the tensile strength of moulded insulating materials (Fig. 193) 
shall be used for this purpose. All loose particles are removed, and the specimen 
dried for 24 hours either in a desiccator or in an oven at 100° C. It is then cooled, 
reweighed, and immersed in distilled water for 100 hours at 77° F. At the end 
of this time, the specimen is removed, wiped dry with a cloth and reweighed. The 
following figures should be recorded; viz.: the original weight of the specimen; 
its dry weight; the saturated weight in grams after 100 hours' immersion; the 
percentage of moisture as received; the percentage of moisture absorbed during the 




V -^-- is" '{98.5 



m\ 



■j-.k. 



^a2min)\ 




^^^>' 



(l2.7mm.f 
Make Steel Mold foHiese Dimensions. Limits t 0.'002 ( O.OSmm.) 

From A. S. T. M. Tent. Standards. 

Fig. 193. — Mould for Ascertaining the Tensile Strength of Bituminized Aggregates. 



100 hours, taking the dry weight as 100 per cent. The average for three specimens 
is reported. 

Tensile Strength. The following tentative test has been proposed for moulded 
insulating materials,^ but may also be adapted to testing the surface course of sheet 
asphalt pavements, asphalt mastic floorings, expansion joints (not containing fabric), 
pipe-sealing compounds, etc. The specimen is cast under pressure to obtain the 
greatest possible density, in a hardened and ground steel mould of the dimensions 
shown in Fig. 193, then immersed in distilled water for 48 hours at 77° F., removed, 
wiped dry and pulled apart on any standard testing machine in air at 77° F., 

1 "Tentative Tests for Molded Insulating Materials" (Serial Designation: D 48-17 T), Proc. Am. 
Soc. Testing Materials, Part I, 778, 1917. 



554 ASPHALTS AND ALLIED SUBSTANCES 

at a speed that will enable the beam to be well balanced. The results of the test 
shall be reported in the following order, viz.: the breaking load in kilograms or 
pounds; the thickness in centimeters or inches as measured by a micrometer at the 
point of fracture; the ultimate tensile strength in kilograms per square centimeter 
or in pounds per square inch as calculated from the actual area of the specimen 
at the point of fracture; the speed in centimeters or inches per minute at which 
the jaws travel during the test. Three such tests should be averaged. 

Compressive Strength. This test has Hkewise been proposed for moulded insulat- 
ing materials/ and is adapted to all bituminized mineral aggregates in which the 
particles do not measure over | in. in diameter. A 1-in. cube is moulded under 
pressure in a hardened steel mould to attain the greatest possible density, and 
immersed in distilled water at 77° F. for 48 hours. Wipe the surface dry and 
place sheets of lead re in. thick both above and below the specimen to adjust 
irregularities. Any standard testing machine may be used, and the load shall be 
applied at such a rate of speed as will permit the beam to be kept well balanced. 
The results of the test shall be reported as follows, viz.: the dimensions of the 
specimen in millimeters or inches; the breaking load in kilograms or pounds at 
the first sign of failure; the average ultimate compressive strength in kilograms 
per square centimeter or pounds per square inch, calculated from the measured area 
of the specimen before the load is apphed; the speed in centimeters or inches per 
minute at which the jaws travel during the test. Three such tests are averaged. 

Transverse Strength. This test is similarly intended for moulded insulating 
materials, '^ but may also be applied to bituminized aggregates containing finely 
divided mineral matter, as in the tensile strength test. 

The material shall be compressed to the greatest possible density in a hardened 
steel mould, ground so its internal dimensions will measure exactly | in. by | in. by 5 
in. The specimen is tested at 77° F. after immersion in distilled water at 77° F. for 
48 hours, all surface water having been removed with a dry cloth, and supported 
on two steel blocks with corners rounded to 1| mm. radius, spaced exactly 100 mm. 
apart, and at equal distances from the ends of the specimen. The load is applied 
by a wedge-shaped pressure piece, the edge of which is rounded to a 3 mm. radius, 
extending across the specimen with the edge parallel to the edges of the two sup- 
ports. The angle of the wedge shall be approximately 45°, and the load applied 
as slowly as possible at right-angles to the specimen, midway between the supports. 
The results shall be reported in the following manner, viz.: the thickness of the 
specimen in milhmeters or inches; the actual breaking load in kilograms or in 
pounds at the first sign of failure; the maximum fibre stress in kilograms per square 
centimeters or in pounds per square inch calculated by the formula 

where S represents the maximum fiber stress, P the load applied, L the distance 
between the supports, B the width of the specimen, and D the depth of the speci- 
men. The rate at which the load is applied is also recorded, also the amount of 
deflection in millimeters or inches. 

1 "Tentative Tests for Molded Insulating Materials" (ferial Designation: D 48-17 T), Proc. Am. 
Soc. Testing Materials, Part I, 780, 1917. 

•"Tentative Tests for Molded Insulating Materials" (Serial Designation; D 48-17 T), Proc. Am. 
l§oc. Testing Materials. Part I, 782, 1917. 



METHODS OF TESTING MANUFACTURED PRODUCTS 555 

Impact Test. This test was originally devised by L. W. Page for testing the 
toughness of rock for road building, ^ having since been adapted by Richardson 
for testing bituminous aggregates.- The bituminous mixture is heated to the lowest 
possible temperature that will permit it being manipulated, and formed by com- 
pression into a cylinder 25 mm. high by 24-25 mm. in diameter, the ends of which 
shall be plane surfaces at right angles of its axis. The hot bituminous mixture is 
compressed in a hollow cj'lindrical steel mould, 24-25 mm. in diameter by 50 mm. 
long, having an accurately fitting steel plunger. The mould is loosely filled with 
the hot bituminous mixture and compressed with the plunger by sharp blows of a 
heavy hammer from the top and bottom respectively, until it is thoroughly com- 
pacted. The cylinder of bituminous material is then knocked from the mould and 
sawed off or ground down until it measures exactly 25 mm. high. The density 
of the specimen should be noted and reported. It shall be maintained in water at 
77° F. for 48 hours, wiped dry, and tested in air at a temperature of 77° F. on any 
form of impact machine which will comply with the following essentials .-^ 

(a) A cast-iron anvil weighing not less than 50 kg. firmly fixed upon a solid 
foundation. 

(6) A hammer weighing 2 kg. arranged to fall freely between suitable guides. 

(c) A plunger of hardened steel weighing 1 kg. arranged to slide freely in a 
vertical direction in a sleeve, the lower end of the plunger being spherical, with a 
radius of exactly 1 cm. 

(d) Means for raising the hammer and dropping it upon the plunger from any 
specified height from 1 to not less than 75 cm. 

(e) Means for holding the cylindrical test-specimen securely on the anvil with- 
out rigid lateral support, and under the plunger in such a way that the centre 
of its upper surface shall, throughout the test, be tangent to the spherical end of the 
plunger at its lowest point. 

The test shall consist of a 1 cm. fall of the hammer for the first blow; a 2 cm. 
fall for the second blow; and an increase of 1 cm. for each succeeding blow, until 
failure of the test specimen occurs. The number of blows required to shatter the 
test-piece is taken to represent the toughness, three such tests being averaged. 
Tests are performed at three temperatures, viz.: 32° F., 77° F. and 115° F. 

Distortion under Heat. This test is appHcable to bituminized mineral aggre- 
gates whose particles do not exceed | in. in diameter, the same test specimen being 
used as in the transversa test (p. 554).^ 

The apparatus used for this purpose is illustrated in Fig. 194. The specimen 
should rest on steel supports 100 mm. apart, and the load appHed on top of the 
specimen vertically and midway between the supports, as in the transverse strength 
test. The machine shall be arranged to apply two different loads, viz.: 2.5 kg. 
and 5.0 kg. The specimen is placed in an air bath surrounded by an oil bath, the 
temperature of which is increased at a rate of exactly 1° F. per minute. The 
deflection of the specimen at its centre between the supports is measured on a 

» Bulletin No. 79, Bureau of Chem., U. S. Dept. of Agr., Wash., D. C; Bulletin No. 44, Office of 
Public Roads, U. S. Dept. of Agr., Wash., D. C, June 10, 1912. 

2 "The Modern Asphalt Pavement," 2nd Edition, 1908, pp. 428 and 585. 

8 " Tentative Tests for Molded Insulating Materials " (Serial Designation: D 48-17 T), Proc. Am. 
Soc. Testing Materials, 17, Part I, 773, 1917. 

i " Tentative Tests for Molded Insulating Materials," (Serial Designation; D 48-17 T), Proc. Am. 
Soc. Testing Materials, 17, Part 1, 787, 1917. 



556 



ASPHALTS AND ALLIED SUBSTANCES 



scale in millimeters or mils. The distortion point shall be considered the tempera- 
ture at which the specimen has deflected 10 mils. The results of the test are 
reported as follows, viz.: the distortion point in degrees F.; the time required 
for the specimen to deflect 10 mils starting at 77° F.; curves are plotted, showing 
the minutes horizontally, and the corresponding deflection, also the temperature 
at given intervals vertically. 

Softening-point. An ingenious apparatus for determining the softening-point of 
moulded insulating materials, which is likewise adapted to testing pavements, 
asphalt mastic floorings, expansion joints and pipe-sealing compounds, has been 



iAte//77c//77 Recording Thermometer 

J-l . Micrometer , — - — Li 




Oage r-^ 

Cover tifts'Xl 
1 off with yL 
Framework 



Oil 
Reservoir 

Oil-Tight 
' Copper 
Tank 

r- Test 
J Specimen 
No. 4 




1 jzza 



From A. S. T. M. Tent. Standards. 

Fig. 194. — Apparatus for Recording Distortion of Bituminized Aggregates under Heat. 

devised by H. R. Edgecomb^ as illustrated in Fig. 195. The underlying principle 
consists in comparing the expansion with the tendency to soften as the tempera- 
ture increaoes. The apparatus consists of an electrical heater 1, a plate or slab 2 
above the heater, a hood 3 for retaining the heat, a rod 4 having a relatively large 
lower face resting loosely on the specimen, a rod 5 having a relatively small lower 
face (0.01 sq.in. in area) actuated by a weight 6 of either 2.5 or 5.0 kg., and an 
opening 7 for the thermometer 8. The rods and thermometer rest upon the insulat- 
ing material 9 to be tested, and each of the rods 4 and 5 is provided with a scale 
10 operating in conjunction with stationary vernier scales 11, for recording the 
DQOvement. 

It is important that the sample 9 be provided with two plane faces, also that the 
temperature is increased at the uniform speed of 1° F. per minute. The positions 
of the rods 4 and 5 are noted at periodic intervals, and two curves plotted with the 
temperature as abscissas and the movement of the rods respectively in thousandths 



» U. S. Pat. 1,184,837 of May 30, 1916, "Device for Testing Plastic Materials." 



METHODS OF TESTING MANUFACTURED PRODUCTS 557 



of an inch as ordinates. These curves will be identical as the material expands 
throughout a certain range in temperature, but when it begins to soften rod 5 will 
change its direction of travel, and instead of moving upward will embed itself in 
the sample. The point at which the two curves diverge represents the softening- 
point of the material. This is shown at 60° F. in the chart illustrated in Fig. 195. 

Separation of the Bituminous Matter and Mineral Aggregate. Bituminized 
aggregates are often separated into their bituminous and mineral components for 
the combined purposes of ascertaining the percentage and nature of the mineral 
constituents, and for examining the 
physical and chemical character- 
istics of the bituminous binder, 
with the object of its identification 
or duph cation. Two methods are 
used, including the hot extraction 
process devised by Forrest, and the 
centrifugal extraction method. 

Forrest's Hot Extraction Method. 
The bituminous mixture should first 
be warmed until it may be broken 
apart without fracturing the mineral 
particles. The extraction is per- 
formed in an apparatus illustrated 
in Fig. 196, consisting of a cylin- 
drical brass jacket surrounding an 
incandescent-light bulb to supply 
the necessary heat, and enclosing 
a brass vessel for holding the solvent, 
which in turn carries a cyhndrical 
basket composed of 80 mesh-wire 
cloth for retaining the sample. Cold 
water is circulated through the in- 
verted conical condenser, which also 
serves to cover the apparatus. 
Weigh out 500 g. of material if 
the mineral particles are coarser 
than ^ in., or 300 g. if they are Fig. 195. — Apparatus for Determining the Soften- 
finer than I in. Place it in the ing-point of Bituminized Aggregates, 
basket and cover with a pad of 

cotton or felt i-^ in. thick. Pour 175-200 c.c. of carbon disulphide into the 
inner vessel, insert the cover and start the extraction by turning on the incan- 
descent light. The extraction is usually completed in 3 hours' time, whereupon 
the apparatus is cooled, the basket containing the mineral aggregate removed, 
dried in an oven and weighed. Any fine mineral particles passing through the 
SO-mesh sieve constituting the basket are recovered by filtering the extract through 
a weighed asbestos Gooch filter as described in Test 21a, washed clean with carbon 
disulphide, dried and weighed. This method is used where the bituminous matter 
is 'to be separated in a pure state for further examination. An alternate method 
consists in measuring the extract in a glass graduate, thoroughly agitating it and 
pouring an aliquot portion into a tared crucible or dish, evaporating the solvent, 




20 JiP 4o so 60 



30 w 



558 



ASPHALTS AND ALLIED SUBSTANCES 



burning the residue and igniting to ash. The fine mineral matter present in the 
entire extract may be calculated from the ash derived from the portion ignited. 

f f "-^ 



r-->\. 





Section C-C. 




Section B-B. 

N e"-- >! 




Section A- A. 

From A. S. T. M. Proc. 

Fig. 196. — Forrest's Hot-extraction Apparatus. 

The total should be added to the coarser mineral aggregate previously separated, 

to arrive at the percentage present. ^ 

Centrifugal Method. The most efficient apparatus of 
this type was designed by C. S. Reeve,^ as illustrated 
in Fig. 197. It consists of a i h.p. vertical motor o, 
capable of making 1100 revolutions per minute at 110 
volts, with either direct or alternating current. Its 
shaft projects into a cyhndrical copper vessel b, having 
a concave bottom and draining into the spout c. A 
circular brass plate d, 9^ in. in diameter supports an 
inverted iron bowl e, 8| in. in diameter by 2ye in* 
high, having a 2 in. circular hole at the top. A brass 
cup / is fastened to the inner side of the bowl, having 

» "Extractor for BituminouB Paving Mixtures," by C. N. Forrest, Proc. Am. Soc. Testing Materials, 
18, 1069, 1913. 

* "Laboratory Manual of Bituminous Materials," let Edition, N. Y., 1916, p. 108. 




Fig. 197.— Centrifugal Ex- 
tractor. 



METHODS OF TESTING MANUFACTURED PRODUCTS 



559 



a circle of i in. holes for the admission of solvent, and terminating in a hollow axle 
which fits snugly through a hole in the centre of the brass plate d. A felt ring 
g, I in. wide and about 0.090 in. thick (cut from No. 80 roofing felt) is firmly 
pressed against the bowl by the milled nut h for which the hollow axle is suitably 
threaded. The axle in turn fits snugly over the shaft of the motor, to which it 
is secured by a slot and cross-pin. 

Weigh 300-500 g. of the bituminous mixture, broken up as previously described, 
into the bowl e, place the felt ring on the rim of the plate d, and bolt them together 
with the nut i. After assembHng the apparatus, pour 150 c.c. of carbon disulphide 
into the bowl through the small holes, place the cover over the copper box b, and 
slowly start the motor, gradually increasing its speed until the carbon disulphide 
extract flows in a thin stream from the spout c into an empty flask underneath. 
When the first charge has drained, the motor is stopped, fresh carbon disulphide 
added, and the operation repeated 4 to 6 times until the extract runs clear. The 
bowl is then removed, inverted, the nut 
unscrewed, and any carbon disulphide re- 
tained by the mineral matter allowed to 
evaporate spontaneously. The mineral 
matter is then dried and weighed. It is well 
to filter the extract through a Gooch crucible 
to recover any mineral matter which may 
have worked its way through the felt ring, 
adding same to the balance of the mineral 
matter. 

Recovery of Extracted Bituminous Matter. 
From the weight of the extracted mineral 
matter, calculate the bituminous matter by 
difference, and evaporate the carbon disul- 
phide extract to exactly this weight. This 
may be conveniently performed by distilling 
and condensing most of the carbon disul- 
phide over an incandescent light or an 
electric stove. The concentrated solution 
is transferred to a tared dish, evaporated 
dry on a steam bath, and the last traces 
of solvent removed in an oven at 105° C. 
until the residue attains the calculated 
weight. The bituminous matter may then 
be examined further, according to any of 
the tests described in Chapters XXVII 
to XXXI inclusive. Due allowance should 
be made for the fact that any non-mineral 
matter insoluble in carbon disulphide (Test 
21 &) will be retained mechanically by the 
extracted mineral matter, which with as- 
phaltic products is relatively unimportant, 
but will amount to a considerable item in the case of tar products (see table p. 483). 

Examination of the Recovered Mineral Aggregate. The presence of any non- 
mineral matter insoluble in carbon disulphide will be revealed by the discoloration 




Fig. 198. 



Courtesy of Howard & ]Morse. 

-Mechanical Sifting Apparatus. 



560 ASPHALTS AND ALLIED SUBSTANCES 

of the mineral particles. In this case, the weight of the latter should be corrected 
by igniting it until all carbonaceous matter is destroyed, and then reweighing. The 
mineral matter may be examined further by Tests 36c, 36e and 36/ (page 539). 
A convenient apparatus for the granularmetric analysis (Test 36e) is illustrated in 
Fig. 198, designed by Forrest.^ 



BITUMINIZED FABRICS 

The finished products falling in this class include sheet roofings, floor 
coverings, waterproof membranes, sheathing and insulating papers, 
expansion joints involving the use of woven or felted fabrics, electrical 
insulating tape, and certain types of wall board (p. 386). As these are 
constructed in many different ways, it will obviously be impracticable to 
describe in detail the analytical methods applicable to each. The ones 
which follow have been devised by the author specifically for examining 
prepared roofings,^ but with these as a starting-point, others may readily 
be evolved for testing floor coverings, waterproof membranes, sheathing 
and insulating papers, etc. 

For all practical purposes, prepared roofings may be divided into the six types 
illustrated in Fig. 199. 

Type A represents a layer of felt saturated and coated with bituminous matter. 
The surface coatings may be either finished plain or dusted with very fine mineral 
matter, and they may be either applied smooth and level or with a veined appear- 
ance (Fig. 122). 

Type B is similar to Type A, but surfaced on both sides with moderately coarse 
mineral matter embedded superficially in the coatings (Fig. 124). 

Type C is similar to Type A, but surfaced on one side with coarse mineral 
matter embedded in the coating (Figs. 125-127). 

Type D is composed of a layer of saturated felt and a layer of burlap or cotton 
duck cemented together and coated on top and bottom with bituminous matter. 
Its surface is finished similar to Type A. 

Type E is composed of two layers of saturated felt cemented together and 
coated with bituminous matter, being finished on the surface similar to Type A. 

Type F is composed of two layers of saturated felt, cemented together with a 
layer of burlap in between, and coated with bituminous matter. Its surface is 
finished as in Type A. 

Where burlap is used, it is usually embedded in the bituminous cementing or 
coating material without previously being saturated, due to the fact that burlap, 
on account of its structure, does not absorb the bituminous saturation in the same 
manner as felt. 

Physical Tests of the Finished Fabric. The finished material is tested for 
pliability, weight, thickness and tensile strength. 

Pliability is tested by cutting lengthwise from the centre of the roU a strip 

i*'A New Device for the Mechanical Analysis of Concrete Aggregates," by C. N. Forrest, Proc. 
Am. Soc. Testing Materials, 6, 458, 1906. 

' "Analysis and Testing of Prepared Roofings," /. Ind. Eng. Chem., 9, 1048, 1917. 



METHODS OF TESTING MA^X'FACTURED PRODUCTS 



561 



1 in. wide, and commencing with the largest, successively bending it around various 
cylinders under water at temperatures of 77 and 32° F., respectively, recording the 
cylinder on which the surface cracks. Five cyhnders are used in the test, meas- 



TYPE 
A 



TYPE 
B 



-Dusting Finish 

■■j-L^-r^ ---.j^P Qiturninous Coating 

-Bitunninizecl Felt 

..-Bottom Bituminous Coating 

"Dusting Finish 



-Modenrtely Coarse Mineral Matter 
-Top Bituminous Coating 



s^l-Bituminized Felt 



b-> -v: r _ _ ; : ; - \ j .-Bottom Bituminous Coating 
WMMiMMMm..-Moderately Coarse Mineral Matter 

—Coarse Mineral Surfacing 

■ -,T'5 5 ".-n'nous Coating 
-i-. '- ' zed Felt 
.■3z":^: 3 '^uminous Coating- 
%.--Dusting Finish 

-Dusting Rnish 
''^ '"Top Bituminous Coating 
-Bitummized Felt 

Burlap Embedded in Bottom 
• 'Bituminous Coating 
^Dusting Finish 
'■■Top Bituminous Coating 
■-Bitummized Felt 
--Bituminous Adhesive 

Bituminized Felt 
S^Boffom Bituminous Coating 
^■'Dusting Finish 
-Top Bituminous Coating 

■Bituminized Felt 

Burlap Embedded in 

Bituminous Adhesive 
'-.'Bituminized Felt 
''CBottom Bituminous Coating 
^'Dusting Finish 

Fig. 199. — Types of Prepared Roofings. 

uring 2|, 2, 1^, 1 and | cm. in diameter, respectively. A convenient apparatus for 
this purpose is showTi in Fig. 200. The roofing should be bent parallel to itself, 
through an arc of 180°, at a uniform speed, and in exactly 2 seconds time. 





Fig. 200. — Mandrels for Testing the PHability of Prepared Roofings. 



The pUabiHty is expressed in figures from 1 to 10, as follows: 

1 May be bent through an arc of 180° in one direction (i.e., flat on itself), and then through an 

arc of 360° in the other direction (i.e., flat on itself) without cracking the surface coatings. 

2 May be bent flat on itself (i.e., through an arc of 180°) without cracking the surface coatincs, 

but will crack when bent through an arc of 360° in the other direction. 

3 Surface cracks when bent throush an arc of 180° (flat on itself). 

4 Surface cracks on the 5-cm. cylinder. 

5 Surface cracks on the 1-cm. cylinder. 



562 



ASPHALTS AND ALLIED SUBSTANCES 



6 Surface cracks on the l^-cm. cylinder. 

7 Surface cracks on the 2-cm. cylinder. 

8 Surface cracks on the 2|-cm. cylinder. 

9 Both the surface and the interior of the sheet crack on the 2j-cm. cylinder without, however, 

cracking entirely through the sheet. 
10 The sheet cracks entirely through on the 2|-cm. cylinder. 

Weight, in lbs. per 100 sq. ft., is determined in accordance with the method 
to be described later. 



V- 



//A/ 



r 1 



/I' 



Fig. 20L — Tensile Strength Specimen. 



PULLEY 



WIRE 




FRONT ELEVATION SIDE ELEVATION 

Fig. 202. — Instrument for Testing the Tensile Strength of Prepared Roofings. 

Thickness, in mils (thousandths of an inch), is determined with a micrometer 
cahper, having flat bearing surfaces about I in. in diameter. 

Tensile Strength is determined by subjecting a specimen cut in the direction 
of the length of the roll and of the dimensions shown in Fig. 201 to a tension which 
is increased at a uniform speed of 3 lbs. per second, the specimen being maintained 
at a uniform temperature of 77° F. during the test. A simple and effective instru- 
ment for finding the tensile strength is shown in Fig. 202. Ten such tests are averaged. 

The author has found that the following three tests will throw considerable 
light on the probable behavior of the bituminized fabric upon exposure to the 
elements. 



METHODS OF TESTING MANUFACTURED PRODUCTS 563 

(1) Heating io 125° F. for 100 Hrs. — A strip of the roofing is cut exactly 
12 iii.Xl2 in., care being taken not to disturb any of the detached mineral matter 
on the surface, and suspended in an oven from a thin wire fastened through holes in 
the upper edge of the strip. The piece of roofing should be allowed to hang freely 
and maintained at a temperature of 125° F. for 100 hrs. At the end of this time 
the roofing is allowed to cool. The pliability, weight, thickness and strength are 
redetermined and the changes from the original figures expressed in percentages. 
Any change in the appearance of the surface should also be noted, e.g., sliding 
of the mineral matter, absorption of the coating by the felt, any yellowing of the 
surface blistering, etc. 

Heating Test No. 1 shows the susceptibility of the roofing to the heat of the 
Bun. The loss in weight is equivalent to the volatile matter; a decrease in thickness 
would indicate that the surface coatings have too low a fusing-point and are 
absorbed by the saturant; a large increase in tensile strength and decrease in 
phability would indicate that the roofing has a tendency to dry out rapidly on 
exposure to the elements. Any yellowing of the mineral matter on the surface 
would indicate the presence of unstable oils in the bituminous coating or saturation. 

(2) Exposure to Air Saturated with Moisture at 77° F. for 100 Hrs. — Accurately 
cut a strip of roofing 18 in. X 18 in., and weigh. Remove the detached mineral 
particles from both sides of the sheet with a moderately stiff brush, and re weigh 
(area equals 2\ sq. ft.). Suspend in a tight box containing sufficient water at the 
bottom to saturate the air with moisture. Cover tightly and allow the specimen 
to remain in the moist air for 100 hours at 77° F. As the moisture enters more 
readily through the cut edges of the sheet than through the surface itself, 6 m. 
should be trimmed from the edges at the termination of the test, leaving a strip 
measuring exactly 12 in. X 12 in., representing the central portion of the original 
specimen, and weighing |- of the latter. Ascertain the weight, thickness and 
tensile strength of the 12X12 portion at the end of the test, and calculate any 
variation in percentage from the original figures. The increase in weight should be 
figured on the basis of the original material including the detached mineral 
matter. 

(3) Immersion in Water at 77° F. for 100 Hrs. This test is run exactly the 
same as the preceding, only in this case the specimen should be immersed entirely 
in water at 77° F. for 100 hours. An 18 in. X 18 in. sheet of roofing should be 
used in making the test, and trimmed to 12 in. X 12 in. before redetermining its 
weight, thickness or strength. 

Tests Nos. 2 and 3 show the susceptibihty of the roofing to the action of damp- 
ness and water. 

A skeleton of the physical tests just described is shown in Table XXXVIII. 

A variation of these tests consists in first subjecting a specimen of the roofing 
to the action of moist air or water for 100 hrs., then drying at 125° F. for 100 hrs., 
re-subjecting to the action of moist air or water for another 100 hrs., and finally 
repeating the drying process for 100 hrs. 

Although these tests throw considerable light on the behavior of the roofing 
towards atmospheric heat and moisture, nevertheless they fail to record one very 
important factor, namely, the effect of atmospheric oxidation. At the present time 
we know of no accelerated test by which this can be accurately measured. The 
effect of oxidation can be recorded only by actually submitting the roofing to an 
exposure test for a lengthy period of time. (See p. 577.) 



564 ASPHALTS AND ALLIED SUBSTANCES 

TABLE XXXVIII— PHYSICAL TESTING OF PREPARED ROOFINGS 





Original 
Material 


After 

Heating to 

125° F. for 

100 hrs. 


After 

Exposing to 

Air Saturated 

with Moisture 

at 77° F. 

for 100 hrs. 


After 

Immersing 

in Water 

at 77° F. 

for 100 hrs. 


Pliability at 77° F ... 


P 

V 


Pi 






Pliability at 32° F .... 








Weight in lbs. per 100 eq.ft 

% Decrease in Weight 

% Increase in Weight 


w 


w—un 

\/ 1 nn 


W2 

W2—W 

XlOO 

w 


Wi 


w 


U'3 —w 

XlOO 

w 


Thickness in Mils 

% Decrease in Thickness 

% Increase in Thickness 


t 


ti 

'"'^xioo 

t 


h-t 
XlOO 

t 


ts-t 
— XlOO 

t 


Tensile Strength at 77° F 

% Decrease in Strength 

% Increase in Strength 


s 


51 

^-^^xioo 


Si 

^-"-xioo 

s 


58 
5 — Si 

XlOO 

5 



Separating Prepared Roofing into Its Component Parts. The mineral matter, 
bituminous matter and fibrous matter are distributed in the following manner: 



1 — Detached 



2 — Embedded in the 

top surface coat- 
ing 
3 — Embedded in the 

bottom surface 

coating 
4 — Admixed with the top surface coating 

(Types A, B, C, D, E r.nd F) 
5 — Admixed with the bottom surface coating 

(Types A, B. C, D, E and F) 
6 — Admixed with the cementing layer 

(Types E and F) 



MINERAL MATTER 

Very Fine Mineral Matter (e.g., finely ground talc, mica or silica) Types A, 
D, E and F (on top and bottom) also Type C (on bottom only). 

Moderately Coarse Mineral Matter (e.g., sand, coarsely ground talc, and 
coarse mica flakes) Type B (on top and bottom). 



Coarse Mineral Matter (e.g., crushed slate, crushed brick or tile, crushed 
feldspar or granite, small pebbles or gravel) Type C (on top only). 



May or may not be present. If present, consists 
of very fine mineral matter (e.g., clay, silica, 
limestone, shale, colored mineral oxides, etc.). 



BITUMINOUS MATTER 

1 — Contained in the top surface coating (all types). 
2 — Contained in the bottom surface coating (all types). 
3 — Contained in the cementing layer (Types D and F). 

4 — Contained in the felt, present in either one layer (Types A, B, C and D) or distributed in several 
layers (Types E and F). 

FIBROUS MATTER 

1 — One or more layers of felt (all types). 
2 — Burlap or other fabric (Types E and F). 



METHODS OF TESTING MANUFACTURED PRODUCTS 565 

The separation of prepared roofing into its component parts is carried out as 
follows : 

Weight Per 100 Sq. Ft. Carefully unpack the roll, taking care not to detach 
any of the mineral surfacing or dusting finish. Weigh the roofing after removing 
the wrapper, ends, nails and lap-cement packed in the core of the roll. Measure 
the length and breadth of the roll with a steel tape, recording the dimensions to 
^ in. Calculate the area in square feet. 

Figure the weight of the finished roofing in lbs. per 100 sq. ft (1) 

Cut eeveral strips exactly 3 in. wide across the sheet. 

Note. — With roofing 36 in. wide, these strips will measure exactly f aq. ft., and with roofing 32 in. 
wide, they will measure f sq. ft Find the weight of each strip in grams. 

Calculate the weight of the roofing in lbs. per 100 sq. ft (2) 

Note — With 36 in. roofing, wt. in lbs. per 100 sq. ft =0.294 Xwt. 3 in. strip in grams. 
With 32 in. roofing, wt. in lbs. per 100 sq. ft. =0.331 Xwt. 3 in. strip in grams. 
Check — Result (1) should equal result (2). 

Detached Mineral Matter. Remove the detached mineral particles from both 
sides of the 3-in. strips with a moderately stiff brush or cloth and re weigh in grams. 

Calculate the weight detached mineral matter in lbs. per 100 sq. ft (3) 

Dry Felt and Burlap; Total Embedded and Admixed Mineral Matter; Total 
Bituminous Matter. Extract one of the 3-in. strips in a Soxhlet extractor with 
benzol. Dry the extracted fabric together with any adhering mineral matter at 
110" C. . Cool in a desiccator and weigh the felt as rapidly as possible before it has 
an opportunity to absorb moisture from the air. Repeat the drying, until the weight 
is constant. Carefully brush off, weigh and set aside the adhering mineral matter. 

Calculate the weight of each layer dry felt or burlap in lbs. per 100 sq. ft (4) 

Note — Use the separated felt or burlap for examining its physical and chemical characteristics 
according to the methods to be described later. 

Separate the mineral matter from the benzol extract by filtering or centrif uging ; 
wash clean with successive portions of benzol, dry and weigh. Combine with the 
mineral matter brushed off the extracted felt. 

Calculate the weight of the total embedded and admixed mineral matter in lbs. per 100 sq. ft. . . . (5) 

Screen through a set of standard sieves of different mesh. A mere inspection 
of the particles retained by the various screens will enable one to distinguish the 
moderately coarse or coarse embedded mineral matter from any very fine admixed 
mineral matter present in Types B and C. 

Calculate the weight of moderately coarse or coarse embedded mineral matter in lbs. per 100 sq. ft. 
for Types B and C; or calculate the combined weight of very fine embedded mineral matter 
and admixed mineral matter in lbs. per 100 sq. ft. for Types A, D, E and F (6) 

Calculate the total weight of bituminous matter in lbs. per 100 sq. ft., i.e., fl] —[(3) +(4) +(5)]. . (7) 

Bituminous Saturation in the Felt. Warm a strip about 2 in. wide cut length- 
wise from the roll, and tear off the coatings as shown in Fig. 203, taking care that 
in so doing as little as possible of the saturated felt is removed with the coatings, 
and, on the other hand, that none of the coatings or cementing layer remain 
adhering to the strip of saturated felt. The sm.all arrows to the left of the various 
types of roofing illustrated in Fig. 199 indicate approximately where the layers 



566 ASPHALTS AND ALLIED SUBSTANCES 

should be separated. This can readily be accomplished with a Httle practice and 
dexterity. Where the roofing is composed of one layer of felt, as in Types A, B, C 
and D, the zone between the arrows a and b should be separated. Where the 
roofing is composed of two layers of felt, as in Types E and F, separate the zones 
between the arrows a and b, also c and d, respectively. In this manner, about 25 g. 
of the saturated felt (free from the coating or cementing layers) are obtained from 
each layer. Weigh and extract each portion separately in a Soxhlet with benzol. 
Dry the extracted felt at 110° C. to constant weight, desiccate and weigh. Cal- 
culate the weight of bituminous saturation by difference, and evaporate the benzol 
extract to exactly this weight. 

Note — Use the residue of bituminous saturation recovered from each layer of felt for examining its 
physical and chemical characteristics, according to the methods described later. 

Calculate the per cent of bituminous saturation carried by each layer of dry felt (8) 

Calculate the weight of bituminous saturation present in each layer of the felt in lbs. per 100 sq. ft. 
[i.e.(8) X(4)] (9) 



Top Coating wif-h smalt 
annount of 5ati/ir-cii'ec/ 
Felt aatfiering 

Safuratecf Felt- with 
the Coatings 




Sfripfsed 'off\ 

Z 



"^^S^ZSZZZZZZZZZZZi. 




Bottom Coating 
with small amoun 
of 5ata rated Felt 
adherinc) ///^ 



Fig. 203. — Method of Stripping the Coatings from the Saturated Felt. 

Weights of Bituminous Matter in the Coatings and Cementing Layer. — In types 
A, B, C and D. The combined weights of bituminous matter in the top and bot- 
tom coatings in lbs. per 100 sq. ft. may be calculated by substracting (9) from (7). 
To find the respective weights of bituminous matter in the top and bottom 
surface coatings, take a 3-in. strip cut across the sheet of roofing, from which the 
detached mineral matter has been removed, and split it lengthwise by tearing the 
felt midway between the points a and 6 (Fig. 199). Weigh and extract each section 
separately in a Soxhlet. Desiccate and weigh the dry felt in each section (and the 
burlap in Type D), also separate and weigh the total embedded and admixed 
mineral matter. Calculate the weight of bituminous saturation present [i.e., weight 
of dry felt X (8)]. From the original weight of each section subtract the combined 
weights of dry felt, bituminous saturation, embedded and admixed mineral matter. 
The difference represents the weight of bituminous matter in the surface coating 
carried by that particular section. 

Calculate the weights of bituminous matter in the top and bottom coats, respectively, in lbs. per 
100 sq. ft (10) 

In Types E and F. Take a 3-in. strip freed from the detached mineral matter 
as previously described, and split it into three sections, by tearing through the 
felt midway between the points a and 6, also c and d, respectively (Fig. 199). 
Weigh and extract each of the three sections separately in a Soxhlet. Separate, 



METHODS OF TESTING MANUFACTURED PRODUCTS 



567 



and in each case weigh the dry felt (also the burlap in Type F) and the total 
mineral matter. Following the method previously described: 

Calculate weights of bituniinous matter in the top and bottom coats respectively in lbs. per 100 

sq. ft (11) 

Calculate weight of bituminous matter in the cementing layer in lbs. per 100 sq. ft. 

Calculate weight of very fine mineral matter admixed with the cementing layer in lbs. per 100 sq. ft. 

Very Fine Embedded Mineral Matter also Admixed Mineral Matter, in the Top 
and Bottom Coatings Respectively. Types A, D, E and F. Take another 3-in. 
strip from which the detached mineral matter has been brushed off, and remove the 
outer layer of the top and bottom coatings respectively, by means of moderately 
rough sand paper. Enough of the surface should be scraped to remove every 
vestige of the very fine embedded mineral matter, and at the same time care should 
be taken not to cut completely through the surface coatings into the saturated felt 
underneath. 

With Types A and D, split the scraped sheets lengthwise midway between the 
points a and b. With types E and F, split the scraped sheets lengthwise midway 
respectively, between the points a and b, also c and d, discarding the central 
section. Extract the scraped outer sections separately with benzol as before, 
recovering and weighing: 

The dry felt present in the respective scraped sections (12) 

The admixed mineral matter present in the scraped sections (13) 

The total bituminous matter present in the surface coating and saturating the felt in the respective 

scraped sections (14) 

The dry burlap (in Type D). 

Calculate the bituminous matter present in the felt in the respective scraped sections 

[(8) -MOO X(12)] (15) 

Hence the bituminous matter present in the surface coating remaining on the respective scraped 

sections = (14) - (15) (16) 

The proportion of very fine mineral matter admixed with the bituminous matter in each coating 

= (13) -^(16) (17) 

Total weight of very fine mineral matter admixed with the respective coatings in lbs. per 100 sq. ft. 

= (17) X(10) [in Types A and D] or (17) X(ll) [in Types E and F] (18) 

And weight of very fine mineral matter embedded in the surface of the respective coatings in lbs. 

per 100 sq. ft. =(6) -(18). 

Nature of the Bituminous Matter in the Coatings and Cementing Layer. Brush 
ofif the detached mineral matter from a surface about 2 sq. ft. in area. Then scrape 




Fig. 204. — Method of Removing the Coatings. 

off the outer portion of the surface coating with a sharp knife. This is accomplished 
by holding the knife at right angles to the sheet of roofing resting on a firm, level 
surface, and rapidly drawing the blade sideways under moderate pressure (Fig. 204). 
Care should be taken to avoid scraping entirely through the surface coating. This is 



568 ASPHALTS AND ALLIED SUBSTANCES 

important. Weigh and then dissolve the scrapings in benzol. Separate the mineral 
matter by filtering or centrifuging, and wash with successive portions of benzol. 
Dry and weigh the mineral matter. Calculate the weight of bituminous matter in the 
scrapings by difference, and evaporate the combined benzol extracts on the water 
bath to exactly this weight, completing the evaporation if necessary in an oven. 
Both surface coatings should be treated separately in this manner. In Type D the 
bottom coating may readily be removed by cooling the specimen in an ice-chest and 
rapidly tearing off the bm-lap, which will carry most of the bottom coat with it. 
This should be extracted, filtered and the extract evaporated to obtain the pure 
bituminous matter present. 

With Type F the central web of burlap may be torn out, and the bituminous 
matter contained in the cementing layer separated in the same manner. 

With Type E the bituminous matter may be separated from the cementing layer 
between the sheets of felt, by cooling in an ice-chest, rapidly tearing the specimen 
in two along the plane of the cementing layer, scraping and separating the bitu- 
minous matter as described for the surface coatings. 

Use the separated bituminous matter for examining its physical and chemical 
characteristics. 

Testing the Raw Felt. Ash. The ash is determined by incineration and 
calculated in percentage. 

Fibres Present. The percentage composition of the fibres is determined micro- 
scopically by staining them with a solution of zinc-chlor-iodide (prepared by dis- 
solving 4 g. of potassium iodide and 0.1 g. of iodine in 12 c.c. of water, and then 
adding 20 g. of zinc chloride), and counting under a microscope having a magnifica- 
tion of about 100 diameters. The individual fibres are recognized by their char- 
acteristic shapes and the colors they are stained by the zinc-chlor-iodide solution. 
The percentages are ascertained by counting the fibres in a number of fields and 
finding their average. The following classes of fibres are reported: 

(Cotton fibres — stained wine-red 
Wool fibres — unstained by the solution 
Jute and manila fibres — stained a yellowish brown 
Mechanical wood pulp — stained lemon-yellow 
\ Chemical wood pulp (sulphite and sulphate) — stained grayish purple to purple 

The following solution has been suggested for distinguishing the different kinds 
of chemical wood pulp, including unbleached and bleached sulphite pulps. ^ The 
fibres are first moistened with a 5 per cent solution of ammonium molybdate and 
then with a solution of paranitroaniline (200 mg. dissolved in 80 c.c. of distilled 
water, to which are added 20 mg. sulphuric acid, sp.gr. 1.767). This stains the 
fibres as follows: 

Mechanical wood pulp bright reddish orange 

Unbleached sulphite pulp faint dull orange to faint brownish 

Bleached sulphite pulp colorless. 

Another reagent recently proposed for this purpose ^ is prepared by mixing equal 
volumes of N/10 ferric chloride and N/10 potassium ferricyanide solutions. The 
moist fibres are immersed for 15 minutes at a temperature of 35° C, removed 
and washed thoroughly with water. They are then immersed in a freshly prepared 

^ "Paper Reagent," by W. J. Schepp, Chemist Analyst, p. 20, September, 1917. 
» "A Method to Distinguish between Bleached and Unbleached Sulphite Pulps," by C. G. Bright, 
J. Tnd. Eng. Chetn., 9, 1044, 1917. 



METHODS OF '^TESTING MANUFACTURED PRODUCTS 569 

red stain composed of: benzopurpurin 4-B extra (Bayer & Co.) 0.4 g.; oxamine 
brilliant red BX (Badische Co.) 0.1 g.; and distilled water 100 c.c. This is main- 
tained at 45° C. for 5-6 minutes, the fibres therupon removed, washed immediately 
with water, and examined under a microscope. Unbleached sulphite pulp, ground 
wood, jute, or any lignified fibres are stained a deep blue (the depth depending 
upon the lignin content); whereas bleached sulphite pulp, soda pulp, rags, wool 
or any thoroughly bleached fibres are stained a brilHant red. 

"Number." This is an arbitrary figure adopted by the trade, corresponding 
to the weight in pounds of a ream consisting of 480 sheets, each measuring 12 in. X 
12 in. 

Thickness. This is expressed in mils. 

Mullen Strength. Since the raw felt is not susceptible to changes in temperature 
(as is the case with the finished roofing) it may be tested for tensile strength by means 
of the Mullen tester.^ The specimen is accordingly tested at room temperature by 
increasing the tension at a uniform speed of 2 lbs. per second until it ruptures. 

Thickness Factor. This is equal to the thickness in mils divided by the " num- 
ber " of the felt. 

Strength Factor. This is equal to the Mullen strength in pounds divided by the 
" number " of the felt. 

Testing the Raw Burlap or Duck. Weight. In the case of burlap and cotton 
duck, the weight is figured as explained on p. 390. 

Thickness. Expressed in mils. 

Mullen Strength. Determined as described for testing the raw felt. 

Bituminous Coating, Saturation and Cementing Compounds. These should be 
examined by the methods described in Chapters XXIX to XXXI inclusive. 

Mineral Surfacing and Admixed Mineral Matter. These may be examined by 
the methods outUned in Test 36 (p. 538). 



BITUMINOUS EMULSIONS 

These include bituminous emulsifying oils used for lajdng dust (" dust 
palliatives " p. 353), also bituminous emulsions used for waterproofing 
Portland-cement mortar and concrete (p. 457). The following products 
are likely to be present, viz.: water, ammonia, various chemicals, bitu- 
minous matter, animal and vegetable oils or fats, other forms of non- 
bituminous organic matter and mineral matter. 

Water is determined as described for Test 25. Ammonia is hberated by render- 
ing alkah with caustic potash and heating. If present, it is detected by its odor, 
and may be determined quantitatively by distilling into a standard solution of sul- 

1 The tensile strength of the dry felt is increased materially by extracting with solvents, but 
it may be made to correspond closely with its original figures, by exposing the desaturated felt 
for 3 days to air at 77° F. completely saturated with moisture, prior to its being tested. The fol- 
lowing figures will illustrate this point, viz.: strength original felt (before extraction), 23. .3 lb. 
(average of 10 tests) ; original felt upon heating to 265° F. for 5 minutes, cooling in a desiccator 
and testing immediately, 26.9 lb.; original felt upon extracting with benzol in Soxhlet for 5 
hours, cooling in desiccator and testing immediately, 36.4 lb.; extracted felt exposed 3 days to 
air at 77° F. carrying 30 per cent moisture, 33.6 lb.; extracted felt exposed 3 days to air at 77° F. 
completely saturated with moisture, 27.6 lb. 



570 ASPHALTS AND ALLIED SUBSTANCES 

phuric acid and retitrating with alkali. The presence of chemicals may be detected 
by boiling with water, acidifying with hydrochloric acid and extracting the bitu- 
minous and fatty substances vs^ith benzol. The chemicals remain in the aqueous 
layer and may be determined by a qualitative or quantitative analysis. Bituminous 
matter is determined by saponifying the material and then extracting the unsaponi- 
fiable constituents as described in Test 39a. The non-bituminous organic matter 
and the chemicals are separated from the bituminous and fatty matters as previ- 
ously described, and the non-bituminous organic matter in turn separated from 
the chemicals by suitable methods. Mineral matter is determined by incinerating 
a weighed quantity of the material and examining the ash as described in Test 36. 
Animal and vegetable oils or fats are examined by Tests 37, 39 and 40 respectively. 

BITUMINOUS PAINTS, CEMENTS, VARNISHES AND JAPANS 

As pointed out in Chapter XXVII, bituminous paints, cements, var- 
nishes, enamels and japans are all characterized by the presence of a vola- 
tile solvent with a bituminous base, combined in the form of " vehicle." 
Depending upon whether or not the bituminous paints and cements 
contain a pigment or filler, they may be divided into two general classes, 
viz. : 

(1) Pigment or filler absent: including bituminous varnishes and 
japans, also certain bituminous paints and cements. 

(2) Pigment or filler present: including bituminous enamels, also 
certain bituminous paints and cements. 

The first class consists of a vehicle made up of a solvent and base. 
The second consists of a pigment or filler combined with a vehicle, 
the latter similarly being made up of a solvent and base. The 
bituminous base may be composed of bituminous matter, with or 
without the presence of animal and vegetable oils or fats, resins or 
metallic dryers. In making an analysis of the paint, cement, varnish, 
enamel or japan, the following components are separated and examined 
viz.: (1) solvent, (2) pigment or filler, (3) base. 

Estimation of Solvent. Rapid method used for determining the percentage of solvent 
present: 

The method devised by A. L. Brown is rapid and gives accurate results, but 
does not recover the solvent for further examination. ^ Deliver 3-4 c.c. of the 
well-mixed material (cements as well as paints of a heavy body should first be 
thinned to fluid consistency with a weighed quantity of pure benzol) from a 10-c.c. 
pipette into a weighed glass flask of 50 c.c. capacity, as rapidly as possible. Stopper 
the flask immediately, weigh, and dilute to the mark with pure benzol. Deliver 
exactly 10 c.c. of the well-mixed material from the pipette upon a weighed ground- 
glass plate, 10 by 15 cm. and 1.5-3.0 mm. thick, supported in a level position. 

1 "Quantitative Determination of Body and Solvent in Varnish," by A. L. Brown, Proc. Am. Soe. 
Testing Materials, 14, Part II, 467, 1914; "Determination of Volatile Thinner in Oil Varnish," by 
E. W. Boughton, Technologic Paper No. 76, Bureau of Standards, Wash., D. C, June 21, 1916. 



METHODS OF TESTING MANUFACTURED PRODUCTS 571 

The diluted material should be flowed gradually on the plate, the object being 
to cover it entirely, without causing the solution to creep over the edges. It is 
recommended that 7 c.c. be delivered first, and the remainder, a few drops at a 
time during the ensuing 2 minutes. The evaporation of the benzol will carry most 
of the solvent with it, and the film is so thin that the solvent will evaporate in 
1^-2^ hours, the plate being weighed every half hour to follow the course of evap- 
oration. Should the material contain a drying oil, the plate must be placed in 
an atmosphere of illuminating gas after the first half hour, replacing it after each 
weighing. The solvent has entirely evaporated when a constant weight is obtained. 
From this calculate the percentage of solvent by weight. An idea of the drying 
quaUties of the film may be gained by placing the glass in a free circulation of 
air after the solvent is eliminated, and weighing it every hour as the film oxidizes, 
until it no longer increases in weight. If the coating has a tendency to dry 
unevenly, a weighed quantity of 50-mesh sea sand, previously dried and ignited, 
may be sifted over the paint in a very thin layer, but so the paint will be visible 
between the grains of sand. This will insure a uniform evaporation of the solvent. 

Method Used for Recovering the Solvent for Its Examination and Identification. 
Distil 100 g. paint in a 500-c.c. flask, connected with a spray-trap and a vertical 
condenser, and pass through it a current of dry steam, the flask being heated in 
an oil bath to 100° C. As the steam passes through, gradually raise the tempera- 
ture of the bath to 130° C. Catch the distillate in a separatory funnel, continuing 
the distillation until the funnel contains 400 c.c. of water. To prevent frothing 
and bumping, it is advantageous to weigh a small piece of broken glass or pumice- 
stone into the flask. Let the distillate stand until it separates into two layers, 
then draw off the water and determine the volume and weight of solvent recovered. 
Weigh out another 100 g. into a 250-c.c. flask and distil without steam over an 
electric stove. Continue the distillation until the residue in the flask reaches a 
temperature of 200° C. This gives somewhat lower results than the first m.ethod, 
but the distillate shoiild be tested for water soluble substances to correct the results 
obtained by the previous method. Turpentine dissolves to the extent of 0.3 g. 
for each 100 c.c. of water condensed. ^ 

Pigment and Filler. Dilute 100 g. of the well-mixed material with 500 c.c. 
of benzol in an 800-c.c. stoppered flask. Let stand in a warm place until the pig- 
ment or filler has settled, then carefully decant the supernatant hquid into a clean 
flask of large capacity. The pigment or filler is shaken up with 250 c.c. more 
benzol, allowed to stand in a warm place until it settles, and the supernatant 
liquid decanted into the second flask. Repeat the treatment with benzol until the 
vehicle has been completely extracted from the pigment. The combined extracts 
are allowed to stand quietly to recover any pigment that may have been carried 
over with the benzol, and then carefully decanted through a weighed Gooch crucible 
provided with an asbestos filter. The residues in the flask and on the Gooch crucible 
are washed with benzol as before, and combined with the balance of pigment or 
filler which is then dried at 110° C. and weighed. The pigment or filler thus 
extracted is used for a qualitative or quantitative analysis (Test 36c). ^ 

Examination of the Base. The combined extracts of the preceding test are 
distilled to a small bulk, transferred to a tared dish, and evaporated in an oven at 

1 ''Some Techical Methods of Testing Miscellaneous Supplies," by P. H. Walker, Bulletin No. 109, 
Revised, Bureau of Chem., U. S. Dept. of Agri., Wash., D. C, Feb. 28, 1910. 

2 "Analysis of Paints and Painting Materials," by H. A. Gardner and J. A. Schaeffer, N. Y., 1911. 



572 



ASPHALTS AND ALLIED SUBSTANCES 



110* C exactly to the calculated weight of the base, by subtracting the weights 
of solvent and pigment or filler from the original weight of material taken for 
examination. When oxidizable substances are present, the final evaporation should 
take place in an atmosphere of illuminating gas. 

The base recovered in this manner will contain the bituminous material (with 
the exception of the " free carbon " which will be separated with the pigments), 
animal and vegetable oils or fats, resins and metallic bases and dryers. It. should 
be tested by the methods described in Chapters XXVIII and XXIX, to identify 
the materials used in its manufacture, or to aid in its duphcation. It may be 
separated into its component parts as follows: 

Method of Analyzing the Separated Base 
Dissolve 50 g. in 150 c.c. benzol. Add 10 c.c. dil. nitric acid (1:1) and boil under a reflux con- 
denser for 5 hour to decompose any metallic soaps (i.e. driers, etc.). Add 150 c.c. water, boil under 
reflux condenser, transfer to a separatory funnel, draw off the aqueous layer, boil with another 100 c.c. 
water, and repeat if necessary until all the metals are removed. 



Benzol Solution: 

Distil to 100 c.c, add 300 c.c. of the saponifying liquid (Test 39), boil under reflux 
condenser for 1 hour, and separate the unsaponifiable and saponifiable constituents 
as described in Test 39. 



Unsaponifiable Matter: 

Examine a small portion by Test 
43. If higher alcohols are present, 
separate the balance by Test 39. 
into: 



Hydrocarbons: 

Contain the 
bituminous sub- 
stances (i.e. as- 
phalt coal-tar pitch 
unsap. matter de- 
rived from fatty- 
acid pitch, etc.). 

Examine by the 
methods included 
in Chaps. XXVIII 
to XXXI inclusive. 



Higher Alcohols 

Etc.: 

Contain cho- 
lesterol etc. de- 
rived from wool 
grease, also the 
ansaponifiable 
constituents 
originally pres- 
ent in resins 
(4 to 8%). 



Saponifiable Matter: 

Separate the fatty and lesi . 
acids as described in Test 37e 



Fatty Acids: 

Include acids 
derived from 
vegetable and 
animal oils or 
fats, also from 
fatty-acid 
pitch. 

(Note "A"). 



Resin Acids: 

Include acids 

derived from 

rosin and the 

resins. 

(Note "B"). 



Aqueous Layer: 
D e t e r m i n e 
percentage gly 
cerol by Test 
40. Multiplj 
this by 10 tc 
estimate per- 
cent of vege- 
table or animal 
oils or fats (tri- 
glycerides) pres- 
ent in the ori- 
ginal substance. 
(Note"C"). 



iqueous Extract: 

Contains the 
metallic bases as 
nitrates. Examine 
qualitatively and 
then quantitative- 
ly for lead, man- 
ganese, cobalt, 
zinc, calcium, and 
magnesium. 

(N.B.— The last 
three used for har- 
dening rosin. The 
metallic dryers 
should not be 
found by ignition, 
since the lead will 
reduced to 
metal by the or- 
ganic matter, and 
volatilized.) 



Note "A" 
The following means are used to distinguish between the fatty acids derived from oxidized vege- 
table or animal oils and fatty-acid pitch respectively: 

Fatty Acids Derived Fatty Acids Derived 

From Vegetable or From Fatty-acid 

Animal Oils. Pitch. 

Lactone Value (Test 376) Less than 25 Greater than 25 

K. and S. Fusing-point (Test 15a) Less than 80° F Greater than 80° F. 

Hardness at 77° F. (Test 9c) Less than 5.0 Greater than 5.0 

Color in Mass (Test 1) Translucent yellow to brown . . . Opaque brown to black 

(Note "5") 

Test qualitatively for rosin by the Liebermann-Storch reaction (Test 43). Fossir resins may be 
distinguished from rosin by determining the saponification, acid and ester values of the mixed resin 
acids. The following figures have been reported on the resin acids separated as described: i 

» "The Determination of Rosin in Varnishes," by A. H. Gill, J. Am. Chem. Soc, 28, 1723, 1906; 
"Shellac Analysis," by E. F. Hicks, 8th Intern. Cong, of Applied Chem., 12, 115, 1912, 



METHODS OF TESTING MANUFACTURED PRODUCTS 



573 



Straight Rosin Varnish. . . 
Resin I; Kauri I Varnish 
Rosin ^; Kauri ^ Varnish. 
Straight Kauri Varnish. . . 

Untreated Rosin 

Untreated Kauri Gum. . . . 



Saponification 
Value. 



182-185 
122-135 

143.5 

130 
165-180 
124 



Acid 
Value. 



160-1G2 
44-62 

88 

45 
155-170 

41 



Ester 
Value. 



22-24 
72-78 
55.5 

85 
0-13 

83 



Other resiuB may be examined in a like manner, although unfortunately, figures are not at present 
available. 

Note " C " 

If this corresponds with the total saponifiable matter present (Test 39), then fatty-acid pitch and 
resins are absent, i 

The following is an outline of a method devised by the author for examining 
the dry films of paints, cements, varnishes, enamels, or japans which have been 
applied to surfaces of metal wood, masonry, or prepared roofing. It often happens 
that none of the original material is available, and it becomes necessary to examine 
the paint after it has been applied to the object intended, and allowed to harden 
or oxidize in the air, either at normal or elevated temperatures. The method has 
been found to yield fairly accurate results. 

Carefully scrape 50.00 g. of the paint or varnish film from the sur'ace to which 
it has been applied, and avoid including any of the underlying surface. ^ From this 
point on the method is outlined in the following table: 

Method of Analyzing Dried Paint Films 
Boil 50 g. scrapings with 350 c.c. of the saponifying liquid (Test 39) under a reflux condenser for 1 
hour. Add 300 c.c. benzol-alcohol (1 : 1), boil, let settle and decant the supernatant liquid into a 
large flask. Repeat the treatment with benzol-alcohol (1 : 1) until most of the soluble constituents 
have been extracted, then combine the extracts and let stand quietly to recover any further settlings, 
which after decantation and washing are added to the main portion of the residue. 



Benzol-Alcohol (1 : 1) 
Extracts: 



Residue: 

Dry in an oven at 100° C, pulverize finely, trans'er to a paper thimble and 
extract in a Soxhlet with benzol-alcohol (2 : 1) for 12 hours. 



Benzol-Alcohol (2 : 1) Extract: 



Combine the benzol-alcohol (2 : 1) and (1 : 1) extracts, evaporated to a 
small bulk, and separate the unsaponifiable and saponifiable constituents 
as described in Test 39. 



Unsaponifiable Matter: 

Examine as described 
p. 572. 



Saponifiable Matter: 

Examine as described 
p. 572. 



Aqueous Layer: 

Examine as described 
p. 572. 



Residue: 

Dry, ignite and weigh. 
This includes pigments and 
fillers, free carbon from tars 
or pitches, also any metallic 
dryers present (Note "A"). 



Note "A" 
This should be examined microscopically (Test 36rf) for fillers, and subjected to a qualitative or 
quantitative chemical analysis. Note that any chrome green, chrome yellow, Prussian blue, etc., are 
transposed by the alkali, and these, also lampblack or carbon blacks are decomposed on ignition, for 
which due allowance must be made. 

> ".Determination of Oil and Resin in Varnish," by E. W. Boughton, Technologic Paper No. C5. 
Bureau of Standards, Wash., D. C, Feb. 19, 1916. 

2 The blade of a safety razor held at right-angles to the surface scraped, and drawn across it 
slowly but firmly has been found convenient for this purpose. 



CHAPTER XXXIII 
WEATHERING TESTS 

Effects of Weathering. All substances undergo a change on being 
exposed to air, moisture and sunlight. Metals undergo corrosion, rocks 
disintegrate, wood decays and animal or vegetable fibres decompose 
by hydrolysis. Bituminous substances are not immune from such action. 
On exposure to the weather (i.e., air, sunlight and moisture) they will 
change physically and chemically. 

In the early days of photography, solutions of asphalt in etherial 
oils such as turpentine, oil of lavender, etc., were used for preparing 
the sensitized photographic film. On exposure to light under the lens 
of a camera, certain changes took place in the asphaltic coating, as 
evidenced by the fact that upon subjecting it to the action of tur- 
pentine, those portions which had been in contact with light became 
insoluble, but those protected from its action readily dissolved in the 
solvent, bringing the photographic image into relief. It took rather a 
long exposure to produce satisfactory images, since asphalt is only 
moderately sensitive to light in comparison with some of the high-speed 
photographic plates in use at the present time. Nevertheless very 
artistic results have been produced by this crude method. It was soon 
observed that certain forms of asphalt were more sensitive than other, 
and Syrian asphalt in particular (p. 135) became very popular on 
account of its purity, solubiUty, hardness and sensitiveness to the fight's 
rays.^ It was subsequently found that the addition of sulphur chloride 
increased the sensitiveness of native asphalts,^ but petroleum asphalts 
were apparently rendered inert in its presence. Further investigations 
revealed the fact that petroleum asphalts free from paraffine are rela- 
tively the most sensitive towards light. ^ 

Maximilian Toch noted that bituminous materials on exposure to 
sunlight decomposed with the fiberation of " free carbon."^ His experi- 

» "Syrian Asphaltum for Printing Plates," C. Fleck, /. Soc. Chem. Ind., 23, 268, 1904. 

*" Increase of Sensitiveness of Asphalt," E. Valenta, Phot. Korr., 47, 236, 1910; "Sensitiveness 
of Asphalt to Light," by A. Rosinger, Chem. Ztg., 36, 243, 1913; "Chemistry of Asphalt and Especially 
Photo-chemical Properties," by Paul Godrich, Monatsh., 36, 535, 1915. 

3 "The laght-Sensitiveness of Petroleum Asphalt," by Paul Godrich, Chem. Ztg., 39, 832, 1915. 

* "The Influence of Sunlight on Paints and Varnishes," by Maximilian Toch, /. Soc. Chem. Jnd., 
27, 311. 1908. 

574 



WEATHERING TESTS 575 

ments indicated that this action was inhibited by incorporating an 
opaque pigment. He pointed out further that animal and vegetable 
oils (triglycerides) are not affected in this manner, and when blended 
with bituminous materials, apparently retard the action. 

Investigations of the weathering of bituminous substances have been conducted 
by Hubbard and Reeve, ^ Church and Weiss, 2 Reeve and Anderton' and Reeve and 
Lewis.* The changes brought about upon exposure to the elements are quite com- 
plicated, involving one or more of the following reactions: 

Evaporation. This represents the gradual loss of volatile constituents on expo- 
sure to air and the sun's heat. Certain bituminous materials evaporate quite 
rapidly, and especially the tars. With any bituminous substance the rate of evap- 
oration depends almost entirely upon the temperature. Other things being equal, 
the higher the temperature the greater the volatilization. The determination of 
volatile matter (Test 6) is usually regarded to be an accelerated evaporation test, 
which is supposed to show in a relatively short time at an elevated temperature, 
what takes place over a lengthy period when exposed naturally to the air and sun. 
This is not, however, strictly correct, as will be explained below. 

Oxidation. This takes place on exposure to air and progresses more rapidly 
at high than at low temperatures. The effect of oxidation is tw^ofoid, and involves 
the direct union of oxygen with the bituminous substances, also the elimination 
of a portion of the hydrogen in the form of water. These two reactions may be 
expressed roughly as follows: 

CxHj,+0 = CxHy_2+H20. 

The absorption of oxygen is accompanied by a gain in weight whereas the 
elimination of hydrogen is accompanied by a loss in weight. At low temperatures, 
these reactions are probably induced to a large extent by the actinic hght rays. 

It is recognized that bituminous substances behave differently when heated in 
an inert atmosphere such as illuminating gas or nitrogen, than when heated under 
similar conditions in air or oxygen. In the former instance evaporation only takes 
place, whereas in the latter, evaporation occurs as before, but this at the same time 
is accompanied by a loss in weight due to elimination of hydrogen, also by a gain 
in weight caused by the absorption of oxygen. The extent and nature of these 
reactions will depend upon the substance itself, and also on the conditions to 
which it is subjected. 

Carbonization. This represents the formation of " free carbon " in the bitu- 
minous material, and is induced by an extensive ehmination of hydrogen as indi- 
cated by the foUovang reaction: 

2CxHy+?/0 = Cx+2+^H20. 

>"The Effect of Exposure on Bitumens," by PrevoBt Hubbard and C. S. Reeve, /. Ind. Eng. 
Chem., 5. 15. 1913. 

« "Some Experiments on Technical Bitumens," Proc. Am. Soc. Testing Materials, 15, 275, 1915. 

» "The Effects of Exposure on Tar Products," by C. S. Reeve and B. A. Anderton, J. Franklin 
Inst., 463, Oct. 1913. 

«"The Effects of Exposure on Some Fluid Bitumens," by C. S. Reeve and R. H. Lewis, J. Ind. 
Chem., 9, 743, 1917. 



576 ASPHALTS AND ALLIED SUBSTANCES 

In other words, it represents the elimination of hydrogen carried to an extreme. 
As a matter of fact, the deposit of free carbon generally contains a small percentage 
of hydrogen, and is rarely composed of pure carbon. (See Hubbard, loc. cit.). 
This reaction progresses most rapidly in sunlight (p. 574) but will similarly take 
place upon subjecting the bituminous substance to a high temperature (see " Over- 
heating," p. o49). 

Polymerization. This is due to a condensation or polymerization of the mole- 
cules, and manifests itself by a hardening or " setting " of the substance.^ This 
polymerization has also been termed " spontaneous hardening " and is comparable, 
in a way, to the hardening or setting of Portland cement. The reaction may be 
expressed as follows: 

nCj;H{^ = KJnx^ny 

Bituminous materials after being freshly melted will appear softer and show a lower 
fusing-point than upon standing a day or two. For this reason it is recommended that 
the hardness and fusing-point be determined on the freshly melted material. Polymeri- 
zation also takes place to a greater or lesser extent on heating bituminous materials 
to a high temperature, and is especially noticeable in fatty-acid pitches, some of 
which set and become infusible in the same manner as china-wood oil upon being 
heated in the neighborhood of 300° C. 

Effects of Moisture. All bituminous substances are more or less affected upon 
exposure to moisture, which manifests itself in two ways, namely by the actual 
absorption of water and by the gradual leaching out of soluble constituents. These 
actions become intensified when the substance has oxidized, since oxygenated sub- 
stances seem to have a greater afiSnity for moisture than the hydrocarbons them- 
selves. 

The moisture-absorbing properties of bituminous substances may be demon- 
strated optically by pasting a postage stamp on a piece of glass and coating it 
with a film of the bituminous substance applied in the form of paint. After the 
solvent has evaporated, the sheet of glass is im^mersed in water. Within 24 to 48 
hours the water will be observed to have permeated the paint film., loosening the 
postage stamp, and forming a blister underneath. 

Exposure to the weather affects the physical and chemical characteristics of 
bivuminous substances in the following manner, viz.: 

(Test 1) Color in mass Becomes lighter; • 

(Test 2) Homogeneity Destroyed by the formation of free carbon; 

(Test 5) Lustre Disappears, the surface becoming dull; 

(Test 6) Streak Often changes from a black to a brown, and some- 
times to a yellow; 

(Test 7) Sp. gr. at 77° F Increases; 

(Test 8) Viscosity Increases; 

(Test 9) Hardness or consistency Increases; 

(Test 10) Ductility Decreases; 

(Test 11) Tensile strength Decreases; 

(Test 12) Adhesive lees Decreases; 

(Test 15) Fusing-point Increases; 

(Test 16) Volatile matter Decreases; 

(Test 17) Flash-point Increases; 

(Test 18) Burning-point Increases; 

(Test 19) Fixed carbon Increases; 

, * "The Testing of Bitum^ens for Paving Purposes," by A. W. Dow, Proc. Am. Soc. Testing 
Materials, 3, 359, 1903. 



WEATHERING TESTS 



577 



(Test 21a) Solubility in carbon disulphide Decreaees; 

('lest 216) Non-mineral matter insoJuble Increases; 

(Test 22) Carbenes Variable; 

(Tc3t 23) Solubility in 88° petroleum naphtha .... Decreases; 

(Test 31) Free carbon Increases; 

(Test 37) Saponifiable constituents Unchanged; 

(Test 39) Un8aponifiable matter Unchanged; 

(Test 40) Glycerol Unchanged. 

The weather-resisting properties of bituminous substances are of primary impor- 
tance in the case of bituminized roof coverings, bituminous paints, cements, varnishes 
and enamels, on account of the relatively thiri layers in which these products are 
customarily employed. 



Date Exfosed- 



Manufacturer 



Ctimp'n Coat'g 



Cump'c Sat'n 



Date Manufactured 



Observations 
When Exp'd 



Predom Color 



Fixed S'pst'n - Amount 



Top Coating - Amount 



Pliability at 25C 



U- 



Tens. Streng. 



Date 
Examined 


A 


B 


C 




D 


E 


F 


G 


H 


Remarks 


a 


b 


a 


b 


a 


b 


c 








_: 






^ 


) 















Fig. 205.— Exposure Test Card. 



Conducting Weathering Tests on Bituminized Fabrics. The following system 
has been adopted by the author for conducting exposure tests on bituminized roof 
coverings, viz.: 

Sections 18 in. by 36 in., or 18 in. by 32 in. depending upon whether the roofing 
is 36 or 32 in. wide, are taken across the sheet, the cutting being sharp and square. 
These are exposed on a platform, composed of | in. tongued and grooved boards, 
preferably pine, having a 2 in. slope to the south, the samples being nailed with 
large-headed galvanized barbed roofing nails at the four corners, midway across 
the 18 in. edges, and at three interm.ediate points along the 36 or 32 in. edges, a 
total of 12 nails being used. A convenient card for recording data both initially 
"and after exposure is illustrated in Fig. 205. 



578 ASPHALTS AND ALLIED SUBSTANCES 

The predominating color is expressed numerically as follows: 1 — white, 2 — fairly white, 3 — some* 
what yellowish, 4— yellow, 5 — light gray, 6 — dark gray, 7- — black, 8 — becoming lighter, 9 — becoming 
darker, 10 — glossy, 11 — dull, 12 — iridescent. 

The amount of soapstone is also recorded in digits, as follows: 1 — much, 2 — considerable, 3 — little, 
4 — very little, 5 — none. 

The character of the soapstone is recorded by: 1- — coarse, 2 — granular, 3 — medium, 4 — fine. 

The amount of the top coating by: 1 — much, 2 — considerable, 3 — little, 4 — very little, 5 — none. 

The character of the top coating: 1 — coarse veining, 2 — moderate veining, 3 — fine veining, 4 — 
barely veined, 5 — smooth. 

The dimensions are recorded in inches measured lengthwise and across the specimen, the thickness 
in mils, the weight in grams, the pliability expressed as on p. 561, and the tensile strength as on p. 562. 

Both the indoor and exposed samples are examined at the following intervals, 
viz.: \ year, 1, 2, 3, 4, 5 and 10 years, and the data recorded on the reverse side 
of the card, in columns A to H inclusive. The condition of the surface is expressed 
in digits as follows: 

(A) the amount of fixed soapstone remaining, expressed as 1 — much, 2 — considerable, 3 — little, 4 — very 

little, 5 — none. 

(B) the amount of weather-coating remaining, expressed as 1 — intact, 2 — considerable.. 3 — little, 4 — 

very little and 5 — none. 

(C) the condition of the exposed surface, expressed as 1 — unchanged, 2 — homogeneous, 3 — mottled, 

4 — smooth, 5 — rough, 6 — few fine checks, 7 — covered with fine checks, 8 — few coarse checks, 9 — 
covered with coarse checks, 10 — checks disappearing, 11 — few blisters, 12 — covered with blisters, 
13 — pitted, 14 — few hair cracks, 15 — covered with hair cracks, 16 — covered with coarse cracks, 
17 — felt exposed in spots, 18 — felt largely exposed. 

(Da) the predominating color of the indoor sample, and 

(Db) the predominating color of the exposed sample expressed as noted previously. 

(E) the amount of "dusting" determined by rubbing the surface with a white cloth and observing 

the amount of weathered bituminous coating removed, designated as 1 — none, 2 — very little, 
3 — little, 4 — considerable, 5 — very much. 

(F) the influence of rubbing on the color, designated as 1 — none, 2 — becomes dull, 3 — becomes rusty, 

4 — becomes lighter, 5 — becomes darker, 6 — becomes glossy. 
(Ga) the pliability of the indoor sample at 77° F. (see p. 561), and 
(Gb) the pliability of the exposed sample at 77° F. 
(Ha) the tensile strength of the indoor sample at 77° F., and 
(Hb) the tensile strength of the exposed sample at 77° F., and 
(He) the percentage increase or decrease in the tensile strength of the exposed sample over that of the 

indoor sample. 

The 8 specimens illustrated in Fig. 206 represent typical surface conditions as 
recorded in column C. The appearance of specimen A may be expressed as 1-2 
(unchanged and homogeneous) ; that of specimen B as 7 (covered with fine checks) ; 
specimen C as 9 (covered with coarse checks); specimen D as 10 (checks disap- 
pearing, meaning that they existed when the previous observation was made, but 
have since largely disappeared); that of specimen E as 11 (showing a few blisters); 
that of specimen F as 15 (covered with hair cracks); that of specimen G as 16 
(covered with coarse cracks); specimen H as 18 (felt largely exposed). These 
photographs were taken after the specimens were exposed to the weather for five 
years. Fig. 207 shows specimens A and H enlarged 3^ diameters. The veined 
surface of A shows up very distinctly, and also the characteristic uneven appearance 
of the roofing when the weather-coating has worn off and the felt fibres exposed, 
as in H. 

" Checking " is distinctly a surface phenomenon which manifests itself with 
certain substances on exposure. The checks rarely extend entirely through the 
bituminous coating, and are seemingly caused by the hardening and contraction 
of the upper stratum, resulting in a tension which is sufficient to cause it to crack 



WEATHERING TESTS 



579 








(G) 




(D) (H) 

Fig. 206. — Effects of Exposure on Smooth-surfaced Prepared Roofings, 



580 



ASPHALTS AND ALLIED SUBSTANCES 



and slide over the softer sub-stratum. Bituminous substances which are largely 
influenced by changes in temperature (in other words having a high susceptibility 
factor) are likely to check. As the " spontaneous hardening " (p. 576) progresses 
downward into the lower layers, the checks gradually disappear. 

Blistering is caused either by the accidental inclusion of globules of moisture 
underneath the bituminous coating, or by using a saturating material carrying an 
abnormally large proportion of volatile constituents. The heat of the sun will 
cause these to gradually vaporize, and the pressure exerted on the weather coating 
forms bhsters. 
t/"" -'-Hair cracks are caused by the contraction of the bituminous material, and take 
place with substances which are hard, brittle, and devoid of elastic properties. The 




(A) (H) 

Fig. 207. — Enlargements of Specimens A and H in Fig. 206. 



action is aggravated by the use of soft plastic saturating maaterials in conjunction 
with a hard and brittle coating. The cracks usually extend all the way through 
the bituminous coating, and will neither seal up nor disappear in time, as is the case 
with the checks. 

The predominating color is a criterion of the rapidity with which the soapstone 
or mineral matter on the surface disappears, and the " dusting " furnishes an indi- 
cation of the rate with which the bituminous coating weathers away on exposure. 
As bituminous substances weather, they form a pulverulent chalk-like mass having 
but Httle coherence, and which is therefore easily removed by wiping with a cloth. 
This corresponds to " chalking " of linseed-oil paint films. The influence of rubbing 
on the color is of supplemental value, furnishing an indication of how deep the 
weathering has progressed. 

The phabiHty of the roofing shows to what extent the roofing has " dried out," 
bearing in mind that when the pliability decreases to a certain extent, the sheet 
can no longer fulfil its function properly, but will break upon being subjected to 
a severe vibratory strain. 

The tensile strength indicates the extent to which the weathering has weakened 
the roofing, also an approximation of its residual wearing qualities. By constructing 
a curve of the tensile strength of the sheet at different intervals, some idea may be 



WEATHERING TESTS 



581 



gained of its probable durability. As the roofing ages indoors, it gradually gains 
in strength, until it finally remains constant. A similar sheet exposed out doors, 
rapidly gains in strength up to a certain point, which corresponds to the disappear- 
ance of its weather coating. The tensile strength will thereupon decrease until it 
falls below the corresponding strength of the indoor sample. The roofing reaches 
its " mean effective life " when the strength curve of the outdoor sample crosses 
the curve of the indoor sample. This will be made clear by Fig. 208 showing the 
strength curves of representative high-grade 1, 2 and 3 ply smooth-surfaced pre- 
pared roofings weighing 32, 42 and 52 lb. net per 108 sq.ft. The solid lines represent 

150 



140 



130 





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I 2 5 4 5 e 7 8 9 10 II 12 13 14 15 16 

Years 

Fig. 208. — Tensile Strength Carves of Prepared Roofings on Exposure. 



the strength of the outdoor samples, and the dotted lines the corresponding strength 
of samples aged indoors. The following figures will interpret the diagram, viz.: 



Original strength 

Maximum strength outdoor sample 

Outdoor sample same strength as indoor . . 
Outdoor sample same strength as originally 



One-ply. 



Years. Lbs 



Two-ply 



Years. Lhs 




10 
\2\ 
13 



70 
120 
90 
70 



Three-ply. 



Years. Lbs 



90 
145 
115 

90 



The mean effective lives of the roofings in question may be taken as 9, 122 and 
15 years respectively, and the maximum effective lives as 10, 13 and \h\ years. 
The life of the roofing may be prolonged by painting it with a high-grade bitu- 
minous paint, before the weather coating has entirely worn away. 



582 ASPHALTS AND ALLIED SUBSTANCES 

Conducting Weathering Tests on Bituminous Paints, etc. Bituminous paints 
may similarly be tested by applying them in one or more coats to steel sheets 
or wooden panels, and observing their appearance at regular intervals. The follow- 
ing features should be recorded: 

(1) Loss of lustre. 

(2) Condition of the exposed surface. 

(3) Amount of dusting. 

(4) Influence of rubbing on the color. 

(5) Any chipping of the paint and exposure of the underlying surface. 

(6) Any corrosion in the case of the steel plates. 

Items 2, 3 and 4 are recorded as in the foregoing tests on prepared roofings, 
and items 1, 5 and 6 in accordance with any convenient scale of measurement. 

Much has been written concerning the methods for performing exposure tests 
on paints, and for further information on this subject, the reader is referred else- 
where. 



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TEMPERATURE CONVERSION TABLE 
Fahrenheit to Centigrade 



F.° 





10 


20 


30 


40 


50 


60 


70 


80 


90 


Frac- 
tional 
Parts 




C. 

-17.7 
37.7 
93.3 

148.8 
204.4 
260.0 

315.0 
371.1 
426.6 

482.2 
537.7 


C. 

-12.2 
43.3 
98.8 

154.4 
210.0 
265.5 

321.1 
376.6 
432.2 

487.7 
543.3 


C. 

-6.6 

48.8 

104.4 

160.0 
215.5 
271.1 

326.6 
382.2 
437.7 

493.3 

548.8 


C. 

-1.1 

54.4 

110.0 

165.6 
221.1 
276.6 

332.2 
387.7 
443.3 

498.8 
554.4 


C. 

+4.4 

60.0 

115.5 

171.1 
226.6 
282.2 

337.7 
393.3 

448.8 

504.4 
560.0 


C. 

+ 10.0 

65.5 

121.1 

176.6 
232.2 

287.7 

343.3 
398.8 
454.4 

510.0 
565.5 


C. 

+ 15.5 

71.1 

126.6 

182.2 
237.7 
293.3 

348.8 
404.4 
460.0 

515.5 
571.1 


C. 

+21.1 

76.6 

132.2 

187.7 
243.3 
298.8 

354.4 
410.0 
465.6 

521.1 
576.6 


C. 

+26.6 

82.2 

137.7 

193.3 
248.8 
304.4 

360.0 
415.6 
471.1 

526.6 
582.2 


C. 

+32.2 

87.7 

143.3 

198.8 
254.4 
310.0 

365.6 
421.1 
476.6 

532.2 

587.7 





100 


F.° 


C.'' 


200 

300 
400 
600 

600 
700 
800 

900 
1000 


1 
2 
3 

4 
5 
6 

7 
8 
9 


0.6 
1.1 
1.6 

2.2 
2.7 
S.3 

3.8 
4.4 
5.0 



Centigrade to Fahrenheit 

























Frac- 


c.° 





10 


20 


30 


40 


50 


60 


70 


80 


90 


tional 
Parts 




r. 


F. 


F. 


F. 


F. 


F. 


F. 


F. 


F. 


F. 




— 


+32 


+14 


-4 


-22 


-40 


-58 


—76 


-94 


— 112 


— 130 






+0 


32 


50 


68 


86 


104 


122 


140 


158 


176 


194 


C,° 


F.° 


100 


212 
392 


230 
410 


248 
428 


266 
446 


284 
464 


302 

482 


320 
500 


338 
518 


356 
536 


374 
554 






200 


1 
2 


1.8 
3.6 


300 


572 


590 


608 


626 


644 


662 


680 


698 


716 


734 


3 


5.4 


400 


752 


770 


788 


806 


824 


842 


860 


878 


896 


914 


4 


7.2 


500 


932 


950 


968 


986 


1004 


1032 


1040 


1058 


1076 


1094 


5 


9.0 


600 


1112 


1130 


1148 


1166 


1184 


1202 


1220 


1238 


1256 


1274 


6 


10.8 


700 


1292 


1310 


1328 


1346 


1364 


1382 


1400 


1418 


1436 


1454 


7 


12.6 


800 


1472 


1490 


1508 


1526 


1544 


1562 


1580 


1598 


1616 


1634 


8 


14.4 


900 


1652 


1670 


1688 


1706 


1724 


1742 


1760 


1778 


1796 


1814 


9 


16.2 


1000 

t 


1832 


1850 


1868 


1886 


1904 


1922 


1940 


1958 


1976 


1994 





Black figures indicate recurring decimals 

Examples: 567° F. =293.33+3.888 =297.22° C; -85° C. = -112-9.0 = -121° F. 

Met. Chem. Eng. 11, 394, 1913; 8, 123, 1910. 



686 



SUBJECT INDEX 



Absorption test of: 

bituminized roofings, 563 
bituminous compositions, 552, 576 
insulating papers, 438 
paints, 576 
Acetone, 41, 188, 466 

solubility in, see "solubility" 
Acetone oils, 188, 189, 465 
Acetylenes, 33 

Acid asphalt, see "sludge asphalt" 
Acid oil distillate, 304 
Acids: 

asphaltous, see "asphaltous acida" 
fatty, see "fatty acids" 
free, see "free acids" 
resin, see "resin acids" 
tar, see "tar acids" 
Acid sludge, see "sludge" 
Acid-sludge asphalt, see "sludge asphalt" 
Acid value, 543 
Adhesive corhpositions, 392 
Adhesive compounds for: 
built-up roofing, 442, 444 
waterproofing, 442 
Adhesive or adhesiveness teat, 481, 506: 
Kirschbraun's, 507 
Osborne's 506 
Aegerite, 151 
Aeonite, 151 
Africa: 

albertite in, see "albertite" 
asphalts in, see "asphalt" 
Aged surface of bituminous materials, 485 
Aggregate, see "mineral aggregate" 
Agitators, 303; 
Air condensers, 174 
Air-drying paints, 472 
Air-drying varnish, 473 
Albania, asphalt in, see "asphalt" 
Alberta, asphalts in, see "asphalt" 
Albert coal, 16, 153 
Albert shale, 162, 221 
Albertite, 153, 482: 
characteristics of, 149 
classification of, 26 
depolymerization of, 56, 314 
discovery of, 16 
distillation of, 221 
metamorphosis of, 56 
Albertite in: 
Australia, 156 
Canada, 153 
United States, 155 
Utah, 155 
West Africa, 156 



Albertite shales, 159 
Alcohols, 41, 185, 188, 189, 466: 
higher, see "higher alcohols" 
Algeria, asphalts in, see "asphalts" 
Alsace-Lorraine, asphalts in, see "asphalts" 
Ammonia, 42, 208, 220, 231, 233, 245 
Ammonium sulphate, 200, 221 
Analysis of: 

bituminized fabrics, 560 
bituminized mineral aggregates, 552 
bituminous cements, 570 
bituminous emulsions, 569 
bituminous paints, 570 
bituminous japans, 570 
bituminous varnishes, 570 
dried paint films, 573 
Analysis, ultimate, 42 
Anhydrides, 543: 

asphaltous acid, see "asphaltous acid anhy- 
drides" 
Animal charcoal, 337 
Animal fats, 317, 341, 549 
Animal oils, 317, 341, 549 
Animal theories, see "theories" 
Animal waxes, 317, 549 
Anthracene, 41, 169, 245, 248, 550 
Anthracene oil, 231, 246, 248 
Anthracite coal, 60, 61, 226, 238, 482: 
classification of, 26 
metamorphosis of, 58, 60 
Anthracoxenite, 59 
Anthraquinone reaction, 481, 550 
Arabia, asphalts in, see "asphalts" 
Arcadian shale, 162, 221 
Argentine, asphalts in, see "asphalts" 
Argulite, 102 
Aristotle on asphalts, 10 
Arkansas, impsonite in, see "impsonite" 
Armature-carbons, 451 
Armored bituminized fabrics, 385 
Artificial asphalts, see "petroleum asphalts" 
Asbestos felt, 390 
Ash in felt, 389, 390, 568 
Asia, asphalts in, see "asphalts" 
Asiatic Russia: 

asphalts in, see "asphalts" 
elaterite in, see "elaterite" 
Asphalt: 

acid, see "acid asphalt" 
acid-sludge, see "acid-sludge asphalt" 
associated minerals, 47 
Barbados, see "Barbados asphalt" 
Bermudez, see "Bermudez asphalt" 
blown, see "blown petroleum asphalt" 
chemistry, of 15, 28 
classification of, 14, 26, 82 
compositon of, 42 



587 



588 



SUBJECT INDEX 



Asphalt — Continued: 

condensed, see "blown petroleum asphalt" 

consumption in U. S., 67 

cracking of, 56, 277 

cut-back, see "cut-back asphalt" 

definition, of, 23' 

discovery in Cuba, 12 

discovery in Trinidad, 12 

distinguishing from fatty-acid pitch, 336 

Dubb's, see " Dubb's asphalt" 

exports from U. S., 66 

extraction of, see "extraction" 

for waterproofing, 442, 443 

geology of, 46 

heating of, 58 

imports into U. S., 66 

LaBrea, see "LaBrea asphalt" 

lakes, 48 

Limmer, see " Limmer asphalt" 

liquid, 82, 268 

Lobsann, see " Lobsann asphalt" 

Maracaibo, see " Maracaibo asphalt" 

metamorphosis of, 55 

native, see "native asphalt" 

Neuchatel, see "Neuchatel asphalt" 

origin of, 14, 55 

origin of word, 1 

oxidized, see "blown petroleum asphalt" 

oxidized petroleum, see "blown petroleum 
asphalt " 

oxygenized, see "blown petroleum asphalt" 

petroleum, see "petroleum asphalt" 

production of, 62, 63, 65 

properties of, 22 

pyrogenous, see "pyrogenous asphalts" 

Ragusa, see " Ragusa asphalt" 

residual, see "residual asphalt" 

rock, see "rock asphalt" 

seepages, 48 

Seyssel, see "Seyssel asphalt" 

sludge, see "sludge asphalt" 

springs, 8, 48 

straight-run, see "straight-run asphalt" 

sulphurized, see "sulphurized asphalt" 

Tataros, see "Tataros asphalt" 

Trinidad, see "Trindad asphalt" 

use by Babylonians, 6 

use by Egyptians, 5 

use by Persians, 4 

use by Sumerians, 1 

use in Biblical times, 6 

Val de Travers, see "Val de Travers asphalt' 

veins, 50 

wurtzilite, see " wurtzilite asphalt" 
Asphalt-bearing shales, see "shales" 
Asphalt block pavements, 7, 373 
Asphalt broken stone pavement, 360 
Asphalt cement, see "asphaltic cement" 
Asphalt-cork composition, 453 
Asphaltenes, 527, 546 
Asphaltic cement, 370 
"Asphaltic coal," 16 
Asphaltic constituents, 481, 545 
Asphalt fillers, 382 
Asphaltic limestones, 26 
Asphaltic petroleum, see "petroleum" 
Asphaltic pyrobitumen, 149 

classification of, 26 

compositon of, 43 

definition of, 24 



Asphaltic pyrobitumen — Continued 

heating of, 58 

metamorphosis of, 52, 55, 57 

origin of, 52 

production of, 62, 64 

properties of, 22 

veins of, 50 
Asphaltic pyrobituminous shales, 56, 158, 159, 
482: 

classification of, 26 

metamorphosis of, 56, 57 
Asphaltic resins, 547 
Asphaltic sands, 71, 94 
Asphaltic shales in Colorado, 66 
Asphalt in: 

Africa, 126 

Albania, 10, 90 

Alberta, 105 

Algeria, 126 

Alsace-Lorraine, 118 

Arabia, 126 

Argentine, 116 

Asia, 91, 125 

Asiatic Russia, 125 

Austria, 120 

Baku. 12 

California, 66, 83, 102 

Canada, 105 

Cuba, 12, 86, 107 

Dead Sea, 6, 11, 51, 125 

Eastern Siberia, 91 

Europe, 90, 116 

France, 13, 90, 116 

Germany, 13, 119 

Greece, 90, 123 

Indiana, 93 

Italy, 122 

Japan, 125 

Kentucky, 66, 82, 92 

Louisiana, 100 

Mesopotamia, 8, 126 

Mexico, 85, 107 

Missouri, 93 

Nigeria, 126 

North America, 82, 92 

Oklahoma, 66, 82, 93 

Oregon, 85 

Persia, 5, 8, 13 

Philippines, 91 

Portugal, 124 

Rhodesia, 126 

Russia, 124 

Siberia, 91 

Sicily, 123 

South America, 86, 108 

Spain, 124 

Switzerland, 14, 117 

Syria, 91, 125 

Texas, 66, 100 

Trinidad, 12, 108 

United States, 82, 92 

Utah, 66, 82, 101 

Venezuela, 17, 86 
Asphaltites, 127, 340: 

classification of, 26 

composition of, 41, 43 

definition of, 23 

geology of, 46, 50 

heating of, 58 

metamorphosis of, 55, 57 



SUBJECT INDEX 



589 



Asphaltites — Continued 

production of, 62, 64 

veins of, 50 

weather-resistance of, 340 
Asphaltites, Lake, 11, 12 
Asphalt-leather mixtures, 454 
Asphalt macadam, see "bituminous macadam" 
Asphalt mastic, 15, 374, 434 
Asphalt mastic floors, 374 
Asphalt mastic foot-pavements, 374 
Asphaltous acid anhydrides, 546 
Asphaltous acids, 546 
Asphalt paints: see "bituminous paints": 

use by Romans, 12 
Asphalt pavements, stone-filled, see "stone- 
filled sheet-asphalt pavements" 
Asphalt-saturated felt, 397, 429 
Asphalt saturator, 396 
Asphalt tiles, 374 
Aephaltum, see "asphalt" 
Asphaltum oil, see "residual oil" 
Austria: 

asphalt in, see "asphalt" 

pyrobituminous shales in, see "pyrobitumiaous 
shales" 
Australia: 

albertite in, see "albertite" 

elaterite in, see " elaterite " 

pyrobituminous shales in, see "pyrobituminous 



B 



Automobile oil, 268 



Babylonians, use of asphalt by, 6 

Baffe-plate separator, 181 

Baffle scrubbers, 175 

Bagga, 76 

Baking japans, 477, 478 

Baking varnishes, 478 

Ball and ring fusing-point method, see "fusing 

point" 
Barbados glance pitch, see "glance pitch" 
Base course, 360, 362, 367 
Base of bituminous paints, 462 
Base of paints, examination of, 571 
Bathvillite, 160 
Battery-box compound, 451 
Battery carbons, 451 
Baum4 scale, 487 
Bedding course, 373 
Benzenes, 38 

Benzine, 211, 267, 281, 464, 466 
Benzol, 38, 227, 232, 245, 250, 465, 466 
Benzol, solubility in, see "solubility in benzol" 
Benzoline, 267 
Bermudez asphalt, 17, 86 
Biblical times, use of asphalt in, 6 
Bibliography, 583 
Binary mixtures, 342 
Binder: 

bituminous, see "bituminous binder" 

close, see "close binders" 

of briquettes, see "briquette binders" 

of sand cores, 251 

open, see "open binders" 
Binder course, 368 
Bitulithic specifications, 364 
Bitumen: 

definition of, 21 



Bitumen — Continued' 
early definition of, 13 
"elastic, " 13 
origin of term, 1 
Bitumens: 

classification of, 26 

composition of, 42 

geology of, 46 

metamorphosis of, 52 

movement of, 50 

occurrence of, 47 

origin of, 46, 52 

properties of, 22 
Bituminated cork mixtures, 453 
Bituminated leather mixtures, 454 
Bituminized fabrics, 386, 560, 577 
Bituminized floor covering, 426 
Bituminized mineral aggregates, 352, 552 
Bituminized tapes, see "electrical insulating 

tapes" 
Bituminized wall board, 440, 560 
Bituminous: 

definition of, 21 
Bituminous adhesive composition, see "adl^csive 

compositions" 
Bituminous binder, 357, 360, 365 
Bituminous broken stone pavements, 360 
Bituminous carpets, see "carpet coat" 
Bituminous cement, 365, 370, 462, 473 

analysis of, 570 
Bituminous coal, 60, 61, 168, 225, 482: 

classification of, 26 

coking, 226 

destructive distillation of, 227 

metamorphosis of, 58 

solubility of, 226 

volatile matter in, 168 
Bituminous coal shales, 159 
Bituminous coating compositions, 392, 437 
Bituminous compositions, 442 
Bituminous concrete pavements, 362 
Bituminous dust-laying oils, 268, 353 
Bituminous emulsions, 351, 354, 458, 569 
Bituminous enamels, 462, 476, 570 
Bituminous expansion joints, 383, 560 
Bituminous fillers, 7, 382 
Bituminous fuels, 454 
Bituminous gravel pavements, 360 
Bituminous japans, 462, 477, 570 
Bituminous lignite, 204 
Bituminous macadam, 360 
Bituminous materials, physical characteristics of 

see "physical characteristics" 
Bituminous matter: 

discovery of in N. Y. State, 16 

discovery of in U. S., 16 

extraction of, 557 

in roofings, 564 

recovery of, 559 

separation from mineral aggregate, 557 
Bituminous mixtures, 338: 

classes of, 348 
Bituminous paints, 462: 

analysis of, 570 

resistance to moisture, 576 

weathering of, see "weathering tests" 
Bituminous paving materials, 352 
Bituminous rubber substitutes, 451 
Bituminous saturating compositions for: 

electrical insulating tape, 439 



590 



SUBJECT INDEX 



Bituminous saturating compositions for — Cont'd: 

flooring fabrics, 426 

insulating and sheathing papers, 437 

prepared roofings, 390 

waterproofing membranes, 429 
Bituminous substf>.nces: 

blending of, 338, 348 

chemical composition of, 42 

chemistry of, 28 

classification of, 12, 19, 26 

consistency of, 338 

r"/ jnition of, 21 

emulsification of, 351, 354, 458 

fluxing of, 339, 340, 348 

fusibility of, 339, 340, 482 

hardening of, 343 

hardness of, 339, 340 

heating of, 349 

improving amalgamation of, 344 

increasing tensile strength of, 345 

making more weatherproof, 345 

overheating of, 350 

preparing mixtures of, 338 

reducing susceptibility of, 344 

rendering war-like, 347 

softening of, 343 

terminology of, 19 

volatility of, 339, 340 

weatherproof properties of, 339, 340 
Bituminous surfacings, 357, 358 
Bituminous varnishes, 462, 474, 570 
Black grease, 326 
Black oil, 268 
Blast-furnace coal tar, 27, 166, 238, 242, 243, 

482 
Blast-furnace coal-tar pitch, 27, 252, 482 
Blau gas, 261 

Blending, methods of, 338, 348 
Blistering, 580 

Blocks, asphalt, see "asphalt block pavements" 
Blower wax, 77 

Blowing, effects of, on asphalt, 290 
Blown asphalt, see "blown petroleum asphalt" 
Blown coal-tar pitches, 255 
Blown Oklahoma asphalts, 100 
Blown petroleum asphalt, 17, 18, 269, 287: 

carelessly prepared, 291 

classification of, 27 

composition of, 43, 289 

from asphlatic petroleum, 294 

from mixed-base petroleum, 294 

from non-asphaltic petroleum, 294 

properties of, 292, 341, 482 

relation between fusing-point and hardness, 293 

relation between fusing-point and sp.gr., 293 

weather-resistance of, 294, 341 
Blue-gas, 257 
Boghead cannel coal, 160 
Boiled tar, 188 
Bombiccite, 59 
Bone charcoal, 337 
Bone fat, 319, 320, 327 
Bone-fat pitch, 317, 328, 332, 335 
Bone grease, refining of, 327 
Bone oil, 337 

Bone tar, 27, 166, 317, 336, 337, 482 
Bone-tar pitch, 27, 317, 336, 337, 341, 482 
Bottom peat, 197 
Boussingault on asphalts, 15 
Branchite, 59 



Brazil, pyrobituminous shales in, see "pyrobitu- 

minous shales" 
Breaking weight, 390 
Brightening of petroleum products, 278 
Briquette binders, 454 
Briquetting, use of coal-tar pitch for, 251 
Browncoal, see "lignite" 
Burgundy pitch, 196 
Burlap, 390, 569 
Burning oil, 267 
Burning point, 481, 520 
Bursting strength, see "Mullen strength" 
Butyrellite, 59 
Byerlite, 18, 287, 289 



Cable pitch, 80 

California, asphalt in, see "asphalt" 

California residual asphalt, see "residual asphalt" 

Canada: 

albertite in, see ' ' albertite ' ' 

asphalt in, see "asphalt " 

pyrobituminous shales in, see " py i obitumiilbus 
shales" 
Canadol, 267, 464 
Candle pitch, 317 
Candle stock, 318 
Candle tar, 317 
Cannel coal, 60, 160, 169, 225 
Cannel coal shales, 159, 160 
Canneloid coal, 60 
Capillarity, 51 
Carbenes, 342, 481, 526 
Carbolic oil, 248 
Carbon, 28, 45, 481, 530 
Carbon disulphide, 466: 

non-mineral matter insoluble in, see "nbn- 
mineral matter " 

solubility in, see "solubility " 
Carbonization of bituminous substances, 350, ^75 
Carbon oil, 267 
Carbons: 

for armatures, see " armature carbons " 

for batteries, see " battery carbons " 

for electric-lights, see "electric-light carbons" 
Carbon tetrachloride, 466, 527 
Carbureting oil, 258 

Carcass -rendering grease, refining of, 327 
Carpet coat, 357 
Carpeting medium, 269 
Cement: 

asphaltic, see "asphaltic cement" 

bituminous, see "bituminous cement" 
Cement waterproofing compounds, 484, 457 
Centrifugal deflector, 178 
Centrifugal method: 

for dehydrating, 182 

for separating bituminous matter, 558 
Centrifugal scrubbers, 177: 

Feld type, 177 

Reading type, 177 

Thiesen type, 177 
Ceresine, 26, 75 
Checking, 578 
Cheese pitch, 115 
Chemical tests, 481, 529 
China-wood oil, 463, 475, 478, 551 
Chloroform, 466 
Cholesterol, 331, 549, 551 
Cholesterol pitch, 317, 329 



SUBJECT INDEX 



591 



Classification of: 

asphalt, 14 

bituminous substances, 12, 19, 26 
Clay, collidal, see "coUodial clay" 
"Clay pigeons, " coal-tar pitch used for, see "coal- 
tar pitch" 
Cleaning oil, 211, 213, 267 
Cleats, roofing, see "roofing cleats" 
Cleveland open tester, see "flash-point" 
Close binder, 368 
Coal: 

Albert, see "Albert coal" 

anthracite, see "anthracite coal" 

asphaltic, see "asphaltic coal" 

bituminous, see "bituminous coal" 

cannel, see "cannel coal" 

canneloid, see "canneloid coal" 

coking, see "coking coal" 

gas, see "gas coal" 

geology of, 46 

glance, see "glance coal" 

parrot, see "parrot coal" 

pitch, see "pitch coal" 

subcannel, see "subcannel coal" 
Coal gas, 14, 31, 227 
Coal oil, 267 
Coal shales, 26, 58, 159 
Coal tar, 225: 

blast-furnace, see "blast-furnace coal tar" 

coke-oven, see "coke-oven coal tar" 

compositon of, 33, 38, 40, 44, 227, 245, 246 

dehydration of, 246 

discovery of, 13 

distillation of, 246 

distilled see "distilled coal tar" 

distinguishing from oil-gas tar, 262 

for saturating purposes, 251 

gas-works, see "gas-works coal tar" 

oxidizing of, 17 

oxidized, see "oxidized coal tar" 

producer-gas, see "producer-gas coal tar" 

production of, 14, 225 

products from, table facing 245 

properties of, 242, 482 

recognition of, 245 

refined, see "refined coal tar" 

refining of, 14, 245 

solvents from, 15, 465, 466 

stills used for, 246 
Coal-tar creosote, see "creosote" 
Coal-tar distillates, 464 
Coal-tar naphtha, see "naphtha" 
Coal-tar pitch, 225: 

blast-furnace, see "blast-furnace coal-tar pitch" 

blown, see "blown coal-tar pitch" 

characteristics of, 253 

classification of, 27 

coke-oven, see "coke-oven coal-tar pitch" 

cut-back, see "cut-back coal-tar pitch" 

discovery of, 13 

for battery-carbons, 251 

for briquetting, 251 

for clay pigeons, 251 

for electric-light carbons, 251 

for joint fillers, 251 

for plastic compositions, 251 

for sand cores, 251 

for waterproofing, 251, 442 

gas-works, see "gas-works coal-tar pitch" 

hard, 251 



Coal-tar pitch — Continued: 

medium, 251 

producer-gas, see "producer-gas coal-tar pitch " 

properties of, 252, 341, 482 

soft. 251 

straight-run, see "straight-run coal-tar pitch" 

water-resistance of, 255, 429 

weather resistance of, 255, 341 
Coal-tar saturated felt, 397, 429 
Coal-tar solvents, 15, 465, 466 
Coating compositions, 392, 437 
Coatings, see "bituminous coatings" 
Coefficient of expansion, 244, 259, 336, 488 
Coke, 200, 212, 232, 269, 279, 282 
Coke-oven coal tar, 166, 225, 233: 

classification of, 27 

production of, 233 

properties of, 243, 244, 245, 482 
Coke-oven coal-tar pitch: 

classification of, 27 

properties of, 252, 482 
Coke ovens: 

beehive, 233 

Koppers, 237 

Otto-Hoffman, 235 

Semet-Solvay, 235 

United-Otto, 236 
Cokey pitch, 115 
Coking coal, 60, 226 

Colloidal clay, 55, 113, 351, 354, 370, 459 
Colombia, glance pitch in, see "glance pitch" 
Color: 

in mass, 481, 484 

of roofing, 580 
Colorado: 

gilsonite, in, see "gilsonite" 

grahamite in, see "grahamite" 

shale in, see "shale" 
Combustion partial, see "partial combustion" 
Complex mixtures, 347 
Compositions or compounds: 

adhesive, see "adhesive compositions" 

batterj--box, see "battery-box compound" 

bituminous, see "bituminous compositions" 

cement-waterproofing, see " cement-waterproof- 
ing compounds" 

chemical, see "chemical composition" 

coating, see " bituminous coating compositions" 

core, see "core compounds " 

electrical, see "electrical insulating compounds" 

insulating, see "electricalinsulating compounds" 

junction-box, see " junction-box compound ' 

moulding, see " moulding compositions" 

pipe-sealing, see "pipe-sealing compounds " 

pot-head, see " pot-head compound " 

saturating, see "bituminous saturating com- 
positions" 

vacuum, see "vacuum-impregnating com- 
pounds" 

waterproofing, .see " waterproofing compounos" 
Composition roofings, see "roofings" 
Compressive strength of bituminized aggregates, 

554 
Compressor oil, 268 

Concrete, bituminous, see "bituminous concrete" 
Condensed asphalt, see "blown petroleum 

asphalt" 
Condensers, 174: 

air, see "air condensers" 

primary, see "primary condensers" 



592 



SUBJECT INDEX 



Condensers — Continued: 

secondary, see "secondary condensers" 

water, see "water condensers" 
Condensing system, 171 
Congo copal, 452, 463 
Consistency test, 481, 494 
Consistency tester, 492, 494 
Consistometer, 498 
Continuous distillation of: 

coal tar, 249 

fatty acids, 319 

lignite tar, 210 

petroleum, 273 

shale tar, 222 
Coorongite, 150 
Coorongitic shale, 164, 221 
Core compounds, 454 
Cork, bituminated, see "bituminated cork 

mixtures" 
Corn oil, 463, 478 

refining of, 327 
Corn-oil-foots pitch, 317, 332 
Corn-oil pitch, 317, 327 
Cotton-oil pitch, 326 
Cotton pitch, 317, 326 
Cotton-seed foots, 326 
Cotton-seed-foots pitch, 317, 332 
Cotton-seed oil, 463 

refining of, 325 
Cotton-seed-oil-foots pitch, 326 
Cotton-seed-oil pitch, 317, 326 
Cotton-seed stearin, 319 
Cotton-stearin pitch, 317, 326 
Course: 

base, see "base course" 

bedding, see "bedding course" 

binder, see "binder course" 

foundation, see "foundation course" 

intermediate, see "intermediate course" 

surface, see "surface course" 

wearing, see "wearing course" 
Covering, bituminized floor, see "bituminized 

floor covering" 
Cracked distillate 282 
Cracking, 56, 165, 173, 272, 282 
Cracking distillation, 272, 282 
Cream-separator oil, 268 
Creosote or creosote oil: 

from coal tar, 248, 379, 430 

from lignite tar, 208, 212, 214 

from, peat tar, 200, 201 

from wood tar, 189, 465 
Creosote preservatives, 16, 379 
Crude scale wax, 308 
Crude wax, 308; 
Cuba: 

asphalts in, see "asphalt" 

discovery of asphalt in, 12 

grahamite in, see "grahamite" 
Cube method for fusing-point, see " fusing-point " 
Cushion, 373, 380 
Cushion layer, 380 
Cut-back asphalt, 277 
Cut-back coal-tar pitch, 251 
Cyclic hydrocarbons, see "hydrocarbons" 
Cyclo-olefines, 37 
Cyclo-paraffines, 34 
Cylinder oil, 268, 278 
Cylinder stock, 278, 280 
Cymogene, 267, 464 



Damar, 452, 463 
Damp-proofing methods, 434 
Damp-proofing paint, 434, 469 
Dead oil, 248 
Dead Sea: 

asphalt in, see "asphalt" 

glance pitch in, see "glance pitch" 
Definition of: 

asphalt, see "asphalt" 

asphaltite, see "asphaltite" 

bitumen, see "bitumen" 

bituminous, see "bituminous" 

pitch, see "pitch" 

pyrobitumen, see "pyrobitumen" 

pyrogenous, see "pyrogenous" 

tar, see "tar" 

wax, see "wax" 
Deflectors, 174, 178 
Degras, see "wool degras" 
Degras oil, 329 
Degras stearin, 329 
Dehydration of: 

asphalts, 68 

petroleum, 269 

tars, 180 
Density, see "specific gravity" 
Depolymerization, 56, 58, 313, 475: 

of albertite, see "albertite" 

of elaterite, see "elaterite" 

of wurtzilite, see "wurtzilite" 
Deposits of asphalt, see "asphalt" 
Deposit: 

primary, see "primary deposit" 

secondary, see "secondary deposit" 
Destructive distillation, 165, 167 
Diacetylenes, 34 
Diazo reaction, 481, 549 
Dimethyl sulphate test, 538 
Dinite, 59 

Diodorus Siculus on asphalt, 11 
Diolefines, 33 
pioscorides on asphalt, 11 
Dippel oil, 337 
bisintegrator, 178 
Distillate oil, 379 
Distillates: 

coal-tar, see "coal-tar distillates" 

petroleum, see "petroleum distillates" 

pyrogenous, see "pyrogenous distillates" 
Distillation : 

continuous, s^e "continuous distillation" 

destructive, see "destructive distillation" 

dry, see " destructive distillation " 

of coal tar, 246 

of hardwood, 185 

of lignite tar, 210 

of ozokerite, 75 

of peat, 200 

of petroleum, 270, 

of rosin, 193 

of shale tar, 222 

of soft wood, 189 

of wood, 184 

fractional, see "fractional distillation" 

intermittent, see "intermittent distillation' 

steam, see "steam distillation" 

vacuum, see "vacuum distillation" 
Distillation olein, 321 
Distillation stearin, 321 



SUBJECT INDEX 



593 



Distillation test, 421, 520: 

flask method, 520 

retort method, 522 
Distilled coal tar, 251 
Distilled-grease olein, 329 
Distortion under heat, 444, 555 
Dopplerite, 59 

Dow ductility test, see "ductility test" 
Dried paint films: 

analysis of, 573 
Dryers, 463, 475 
Dubb's asphalt, 269, 294 
Duck, 390, 569 
Ductility test, 481, 502, 
Durability of: 

paints, 582 

roofings, 408, 581 
Dust, see "fillers" 
Dust catchers, 238 
Dusting, 578 

Dust-laying oils, 268, 353 
Dust palliatives, 353 
Dust preventatives, 353 
Duxite, 59 
Dynamo oil, 268 
Dysodile, 59 



E 



Earth, fullers', see "fullers' earth" 

Earth wax, see "mineral wax" 

Earthy peat, 198 

Eastern Siberia, asphalts in, see "asphalts" 

Ebano, 28.9 

Egypt, glance pitch in, see "glance pitch" 

Egyptians, use of asphalt by, 5 

"Elastic bitumen," 13 

Elaterite, 149, 150, 482: 

classification of, 26 

depolymerization of, 56 

discovery of, 13 

distinguishing characteristics of, 149, 482 

metamorphosis of, 56 
Elaterite in: 

Asiatic Russia, 150 

Australia, 150 

England, 150 
Electrical insulating compounds, 447, 448 
Electrical insulating japans, see "japans" 
Electrical insulating tape, 439, 560 
Electrical insulation: 

bituminized papers for, 438 

montan wax for, see "montan wax" 
Electrical method for dehydrating petroleum, see 

"petroleum" 
Electrical precipitators, 174, 180 
Electric-light carbons, 451 
Elements in bituminous substances, 42 
Elliot closed tester, see "flash point" 
Elutriation test, 363, 541 
Emulsification, 351, 354, 459 
Emulsions, see "bituminous emulsions" 
Enamels, bituminous, see "bituminous enamels" 
Engine distillate, 267 
Engine oil, 268 
England: 

elaterite in, see "elaterite" 

hatchettite in, see "hatchettite" 

pyrobituminous shales in, see "pyrobituminous 
shales" 



Engler viscosity, 491 

Enriching oil, 258 

Esterfication, 545 

Ester value, 544 

lOuosmite, 59 

Europe, asphalts in, sec "asphalt" 

Evaporation of bituminous materials, 575 

Examination of, see "analysis of": 

aggregates, see "aggregates" 

broken slag, see "slag" 

broken stone, see "stone" 

filler, see "filler" 

sand, see "sand" 
Expansion, coefficient of, 244, 259, 336, 488 
Expansion joints, see "bituminous expansion 

joints" 
Export oil, 281 

Exposure test, 345, 577, 582 
Extraction with solvents, of 

California sand asphalt, 73 
Extraction with water of: 

Alberta asphaltic sand, 71, 72 

Alsace-Lorraine asphaltic limestone, 72 

Bastennes asphaltic limestone, 72 

Mexican asphaltic sand, 71 

Oklahoma asphaltic sand, 71, 72, 99 

ozokerite, 72, 75 

San Valentino asphaltic limestone, 72 

Seyssel asphaltic limestone, 72 

Tataros asphaltic limestone, 72, 121 

Texas asphaltic limestone, 72 
Extractors, 72, 178, 180 



Fabrics: 

armored, see "armored bituminized fabrics' 

asbestos, see "asbestos felts" 

bituminized, see "bituminized fabrics" 

felted, see "felted fabrics" 

flooring, see "flooring fabrics" 

insulating, see "insulating fabrics" 

roofing, see "roofing fabrics" 

sheathing, see "sheathing fabrics" 

•waterproofing, see "waterproofing fabrics" 

woven, see "woven fabrics" 
Fastening devices for roofings, 415 
Fat: 

animal, see "animal fat" 

bone, see "bone fat" 

neutral, see "neutral fat" 
Fat pitch, 317 
Fats and oils: 

hydrolyzing of, 318 

refining of, 317 
Fatty-acid pitch, 317, 320, 341, 482: 

behavior on heating, 332 

characteristics of, 333 

classification of, 27 

coefficient of expansion, 336 

distinguishing from asphalts, 336 

for baking japans, 332, 477, 478 

for varnishes, 333 

from bone-fat, 332, 335 

from cotton-seed-oil foots, 332, 335 

from corn-oil foots, 332, 335 

from garbage, 332, 335 

from lard, 332, 334 

from packing-house refuse, 332, 335 



594 



SUBJECT INDEX 



Fatty-acid pitch — Continued: 

from palm oil, 332. 335 

from tallow, 332, 335 

from sewage, 332, 335 

from wool-grease, 332, 335 

properties of, 330, 333 

weather-resistance of, 332, 336, 341 
Fatty acids, 41, 543, 544, 572: 

distillation of, 319 
Feld system of cooling, 249 

analysis of, 568 
Felt: 

asbestos, see "asbestos felt" 

asphalt-saturated, see "asphalt-saturated felt" 

coal-tar-saturated, see "coal-tar-saturated felt" 

microscopic examination of, 568 

rag, see "rag felt" 

roofing, see " roofing felt" 

slaters', see "slaters' felt" 

tarred, see "tarred felt" 
Felted fabric, 386 
Fibre stress, 554 
Fibres in felt: 568 
Fibrous matter, 452, 564 
Fibrous peat, 198 
Fibrous wax, 76 
Fichtelite, 59, 
Fillers, 346, 393, 402, 452, 463, 539: 

asphaltic, see " asphaltic fillers" 

bituminous, see " bituminous fillers" 

examination of, 541, 571 

incorporation of, 350 

joint, see " joint fillers " 

mineral, see " mineral fillers" 

pitch, see "pitch fillers" 
Filters. 174, 180 
Fish oil, 463, 478 
Fixed carbon, 481, 520 
Flash-point, 464, 481, 517: 

Cleveland open tester, 519 

Elliot closed tester, 519 

N. Y. State closed tester, 519 

Pensky-Martens closed tester, 517 
Flask method of distillation, see "distillation 

test" 
Flavins Josephus, on asphalt, 11 
Float test, 493 

Flooring fabrics, see " bituniunized floor cover- 
ings" 426:. 

testing of, 560 
Floor oil, 268 

Floors, asphalt mastic, see "asphalt mastic" 
Flotation oils, 189, 455 
Flotation process, 455 
Flowing temperature, 444, 515 
Flow point see "flowing temperature" 
Flux, 268, 285, 343: 

Pittsburgh, see "Pittsburgh flux" 

"Ventura, see "Ventura flux" 
Fluxing, 339, 343 
Fluxing oil, 274 
Flux oil, 268, 282 
Foot paths, see "asphalt mastic" 
Foot pavements, see "asphalt mastic" 
Foots oil, 278, 279, 308 
Forrest's hot extraction method, 557 
Fossil resins, 56, 463, 475,551, 572 
Foundation course of: 

asphalt block pavements, 373 

bituminous concrete, 362 



Foundation course of — Continued: 

bituminous macadam, 360 

sheet asphalt pavements, 367 

wood-block pavements, 378 
Fractional cooling, see "Feld system" 
Fractional distillation, 270 
Fracture, 481, 485 
France, asphalts in, see "asphalt" 
Free acids, 543 

Free carbon, 342, 481, 534, 575 
Free mineral matter, see "mineral matter" 
Fuel lignite, 204 

Fuel oil, 267, 277, 278, 279, 280, 281, 283, 454, 464 
Fuel ratio, 60 

Fuels, bituminous, see " bituminous fuels" 
Fullers' earth, 278, 281, 308, 393 
Fullers' grease, 329 
Fullers' -grease pitch, 317, 329 
Fu8ing-point,481,510: 

ball and ring method, 513 

cube method, 514 

Kramer-Sarnow method, 510 



Gulicia, ozokerite in, see "ozokerite" 
Garbage grease, refining of, 328 
Garbage pitch, 317, 328, 332, 335 
Gas: 

Blftu, see "Blau gas" 

coal, see "coal gas" 

illuminating, see "illuminating gas" 

marsh, see "marsh gas" 

natural, see "natural gas" 

oil, see "oil gas" 

oil-water, see "oil-water gas" 

Pintsch, see "Pintsch gas" 

water, see "water gas" 
Gas coal, 226 
Gas-engine oil, 268 
Gas hquor, 232 
Gas oil, 173, 211, 213, 223, 257, 258, 267, 277 

278, 279, 280, 281, 283, 464 
Gasoline, 267, 277, 278, 279, 280, 281, 283, 464 
Gas pressure, 51 
Gas-works coal tar, 166, 227, 242, 482: 

classification of, 27 

coeflBcient of expansion of, 244 

composition of, 244, 245, 253 

distillation of, 246 

from horizontal retorts, 242 

from inclined retorts, 242 

from vertical retorts, 242 

properties of, 243, 482 

recovery of, 230 

refining of, 245 

separation of, 230 

yield of, 231 
Gas-works coal-tar pitch, 482* 

characteristics of, 253 

classification of, 27 

properties of, 252, 482 
Gas-works retort, 227: 

continuously operating, 229 

horizontal, 227, 229 

inclined, 227, 229 

vertical, 227, 229 
Geological formations, 46 
Geology of: 

asphaltites, see " asphaltites " 

asphalts, see "asphalts" 



SUBJECT INDEX 



595 



Geology of — Continued. 

bitumens, see "bitumens" 

coals, see "coals" 

mineral waxes, see "mineral waxes" 

non-asphaltic pyrobitumens, see "non-asphal- 
tic pyrobitumens " 

petroleum, see "petroleum" 

pyrobitumens, see "pyrobitumens" 
Geomyricite, 59 
Germany: 

asphalts in, see " asphalt " 

pyrobituminous shales in, see "pyrobituminous 

Gilsonite, 127, 482: 

characteristics of, 128 

classification of, 26 

discovery of, 17 

"firsts," 129 

for manufacturing paints, 129, 471, 478 

mining methods, 133 

mixtures with linseed oil, 471 

mixtures with residual oil, 129 

production in U. S., 64 

"seconds," 129 

"selects," 129 
Gilsonite in: 

Colorado, 127 
! United States, 130 

Utah, 66, 127, 130 
Glance coal, 59 
Glance pitch, 133, 482: 

characteristics of, 127, 133 

classification of, 26 

for manufacturing varnishes, 135 
Glance pitch in: 

Barbados, 134 

Colombia, 135 

Dead Sea, 135 

Egypt, 136 

Mexico, 134 

South America, 135 

Syria, 135 

West Indies, 134 
Glycerine, see "glycerol" 
Glycerol, 481, 543, 549 
Goudron, 317 
Grahamite, 136, 482: 

characteristics of, 127, 136 

classification of, 26 

discovery of, 16 

distillation of, 221 

fluxing of, 349 

mixtures with residual oil, 141, 147 

production in U. S., 64 
Grahamite in: 

Colorado, 143 

Cuba, 144 

Mexico, 144 

Oklahoma, 140 

Texas, 139 

Trinidad, 146 

United States, 137 

West Virginia, 137 
Granularmetric analysis, see "mineral matter" 
Gravitation, 51 

Gravity, see "specific gravity" 
Grease: 

bone, see "bone grease" 

carcass-rendering, see "carcass-rendering 
grease" 



Grease — Continued: 

garbage, see "garbage grease" 

packing-house, see "packing-house grease" 

refuse, see "refuse grease" 

sewage, see "sewage grease" 

wool, see "wool grease" 

yellow, see "yellow grease" 
Greece, asphalt in, see "asphalt" 
"Greek fire," 10 
Green oil, 222 

H 
Hair cracks, 580 
Hannibal on asphalt, 10 

Hardening, spontaneous, see "spontaneous hard- 
ening" 
Hardness scale, 495 
Hardness test, 481, 494 
Hard wax, 76 

Hardwood, distillation of, see " dictillation " 
Hardwood tar, 191, 482: 

characteristics of, 191 

classification of, 27 
Hardwood-tar pitch, 192, 482: 

characteristics of, 192 

classification of, 27 
Hartine, 59 
Hartite, 59 
Harvester oil, 268 
Hatchettine, see " hatchettite " 
Hatchettite, 15, 78 
Hatchettite in: 

England, 79 

Scotland, 79 
Head-light oil, 267 
Heat, effect of, 52, 58 
Heating in flame, behavior on, 509 
Heat tests, 481, 509, 555: 

of bituminized fabrics, 563 
Heavy acetone oils, 189, 465 
Heavy oils: 

from coal-tar, table facing 245 

from wood, 188 
Herodotus on asphalt, 8 
Higher alcohols, 543, 549 
Hill peat, 197 
Hippocrates on asphalt, 10 
Historical review, 1 
Hofmannite, 59 
Homogeneity test, 481, 484 
Horizontal retort, 171, 227 
Hubbard consistency tester, 492 
Hubbard pycnometer method, 489 
Hurdle scrubbers, 175 
Hutchison tar tester, 492 
Hydraulic main, 174, 230, 231, 260 
Hydrocarbons, 28, 543, 548: 

acetylene series, 33 

aliphatic, see "open chain" 

aromatic, see "cyclic" 

benzenes, 38 

cyclic, 30, 34 

cyclo-olefines, 37 

diacetylene series, 34 

diolefine series, 33 

naphthene series, 34 

olefine series, 32 

olefine-acetylene series, 33 

open chain, 29, 30 

paraflBne series, 30 



596 



SUBJECT INDEX 



Hydrocarbons — Continued: 

polycyclic polymethylenes, 37 
polycyclic polynaphthenes, 38 
ring, 30, 34 
terpenes, 37 

Hydrogen, 28, 45, 481, 530 

Hydrolene, 289 

Hydrolysis of oils and fats by: 
ferments, 324 
mixed process, 322 
sulpho-compounds, 322 
sulphuric acid, 321 
Twitchell's process, 323 
water, 318 

Hydrolyzing fats and oils, 318 

Hydrometer method, 486 

Hydrostatic pressure, 51, 431 



Ice-machine oil, 268 

Ichthyol, 121 

Identification of, see "analysis of" 

Illuminating gas: 

discovery of, 13 

enriching of, 231, 258 

manufacture of, 227, 254 

yield of, 232, 258 
Illuminating oil: 

from lignite tar, 213 

from petroleum, see "kerosene" 

from shale tar, 223 
Immersion test, see "absorption test" 
Impact test, 555 

Imports of asphalts into U. S., see "asphalts" 
Impregnating compounds, see "bituminous 

saturating compounds" 
Impsonite, 149, 156, 482: 

characteristics of, 149, 156 

classification of, 26 

metamorphosis of, 56 
Impsonite in: 

Arkansas, 157 

Nevada, 157 

Oklahoma, 157 

United States, 157 
Inclined retort, 171, 227 
Indiana asphalts in, see "asphalts" 
Individual shingles, see "shingles" 
Inorganic theories, see "theories" 
Insulating: 

compounds, see "electrical insulating com- 
pounds" 

fabrics, 386, 560 

japans, see "japans" 

papers, 433, 438, 560 

tape, see "electrical insulating tape" 
Insulation: 

cold, see "insulating papers" 

cold-storage, see "insulating papers" 

electrical, see "electrical insulating com- 
pounds" 

heat, see "insulating papers" 
Integral waterproofing: 

compounds, 457 

method, 434, 457 
Intermediate course, 368 
Intermediate oil, 223, 267 
Intermittent distillation processes, 210, 222, 247, 

270, 319 



lonite, 59 
Iron pitch, 115 
Italy, asphalt in. 



"asphalt' 



Japan, asphalts in, see "asphalt" 

Japans, see "bituminous japans" 

JeJly, petroleum, see "petroleum jelly" 

Jet, 60 

Joadja shale, 164 

Joint filler, 382 

Joints, see "bituminous expansion joints": 

preformed, see "preformed joints" 
Junction-box compound, 450 

K 

Kabaite, 79 

Kapak, 313 

Kaumazite, 203 

Kauri gum, 452, 463, 573 

Kauri varnish, 573 

Kentucky, asphalts in, see "asphalt" 

Kerosene, 267, 277, 278, 279, 280, 281, 282, 283, 

303, 464, 466 
Kerosene shales, 164 , 

Kettles, see "melting tanks" 
Keltte, varnish, see "varnish kettle" 
Killed foots, 326 
Kimmeridge shales, 163, 221 
Kindebal, 77 

Kirschbraun adhesive test, see "adhesive test" 
Koflachite, 59 
Kontakt, 323 
Korite, 289 
Kramer-Sarnow method for fusing-point, see 

" f using-point " 



LaBrea asphalt, 89 

Lactones, 330, 331, 543 

Lactone value, 543 

Lake Asphaltites, 11, 12 

Lakes, 48 

Lake, Trinidad, see "Trinidad Lake asphalt" 

Laminated roofings, see "roofings laminated" 

Lamp oil, 267 

Land asphalt, see "Trinidad land asphalt" 

Lard oil, 463 

Laying roofings, see "roofings" 

Laying shingles, see "shingles" 

Lep, 77 

Leather, bituminated, see " bituminated leather 

mixtures" 
Leucopetrin, 59 
Leucopetrite, 59 
LiboUite, 156 

Libermann-Storch reaction, 481 , 551 
Light acetone oils, 189, 465 
Light oil: 

from coal tar, table facing 245, 246, 248 

from wood, 188 
Light petroleum, 267 
lignite, 59, 61, 204: 

bituminous, see "bituminous lignite" 

briquetting of, 205, 209 

classification of, 26 

distillation of, 211 

fuel, see "fuel lignite" 

met9,morphosi3 of , 58 59 . 



SUBJECT INDEX 



597 



"Lignite— Continued: 

non-bituminous, see "non-bituminous lignite" 

properties of, 482 

retort, see "retort lignite" 

volatile matter in, 168 
Lignite shales, 58, 159 
Lignite tar, 166, 203: 

classification of, 27 

composition of, 41 

discovery of, 14 

properties of, 209, 482 

refining of, 210 
Lignite-tar pitch, 203, 341: 

characteristics of, 214, 550 

classification of, 27 

properties of, 215, 482 

weather-resistance of, 341 
Lignitic shales, 26, 159, 161, 164 
Ligroin, 267 

Limestone, asphaltic, see "asphaltic limestone" 
Limmer asphalt, 13, 119 
Linseed, oil, 463, 471, 475, 478 
Liquid paraffine, 269 

Livingston, process for refining petroleum, 274 
Lobsann asphalt, 118 
Lothian shale, 163, 221 
Louisiana, asphalt in, see "asphalt" 
Lubricating oil: 

from lignite-tar, 211 

from peat-tar, 201 

from petroleum, 268, 277, 278, 279, 280, 281, 
283,303 

from shale tar, 223 
Lustre, 481, 485 

M 

Macadam, see "bituminous macadam" 

Machine oil, 268 

Magma oil, 329 

Maltha, 25 

Malthenes, 527 

Manila copal, 452, 463 

Manjak, 63, 134, 146 

Manufactured products, testing of, 552 

Maracaibo asphalt, 89 

Marble wax, 76 

Marco Polo on asphalt, 12 

Marcus Vitruvius on asphalt, .11 

Marsh gas, 31, 53 

Masonry paints, 469 

Mastic, asphalt, see "asphalt mastic" 

Matka, 77 

Mechanical analysis of aggregates, see "mineral 

aggregate" 
Mechanical scrubbers, 174, 177 
Melanchyme, 59 
Mellite, 59 

Melting, behavior on, 509 
Melting point, 510 

see also "fusing-point" 
Melting tanks, 69 

Membrane waterproofing, 428, 434, 560 
Mesopotamia, asphalts in, see "asphalt" 
Metamorphosis of: 

anthracite coal, see "anthracite coal" 

asphalt, see "asphalt" 

asphaltic pyrobitumen, see "asphaltic pyro- 
bitumen" . 

asphaltic pyrobituminous shales, see "asphaltic 
pyrobituminous shales" 



Metamorphosis of — Continued: 
asphaltites,see "asphaltites" 
bituminous coal, see " bituminous coal" 
bitumens, see "bitumens" 
coal shales, see " coal shales" 
elaterite, see "elaterite" 
inipsonite, see "impsonite" 
lignite, see "lignite" 
lignite shales, see "lignite shales" 
mineral waxes, see " mineral waxes" 
peat, see "peat" 
ozokerite, see "ozokerite" 
wurtzilite, see " wurtzilite " 
Methods of examination, see "analysis" 
Mexico : 

asphalt in, see "asphalt" 
glance pitch in, see "glance pitch" 
grahamite in, see "grahamite" 
Microscopic examination of: 
bituminous substances, 484 
fibres, 568 
mineral matter, 539 
Middle oil, table facing 245, 246, 248 
Middletonite, 59 
Middlings, 267 

Mill, paint, see "paint grinding mill" 
Mineral aggregate: 

bituminized, see "bituminized mineral aggre- 
gate" 
examination of, 539, 559 
granularmetric analysis of, 539, 559 
of asphalt mastic, 377 
of bituminous concrete pavements, 362 
of bituminous macadam, 360 
of bituminous surfacings, 358 
of sheet asphalt pavements, 369 
separation from bituminous matter, 557 
Mineral colza oil, 268 
Mineral fillers, 346, 393, 436, 539 
Mineral matter, 481, 538: 
admixed, 393, 567 
chemical analysis of, 539 

combined with non-mineral constituents, 539 
granularmetric analysis of, 539, 559 
microscopic examination of, 539 
separation from bituminous matter, 557 
specific gravity of, see "specific gravity" 
surfacings of, see "surfacings" 
uncombined, 539 
Mineral oil, see "petroleum" 
Mineral seal oil, 268 
Mineral sperm oil, 268 
Mineral surfacings, see "surfacings" 
Mineral waxes, 74, 307, 340, 482: 
behavior on heating, 58 
classification of, 26 
composition of, 32 
definition of, 23 
geology of, 46 

metamorphosis of, 55, 56, 57 
properties of, 22 
solubility of, 467 
Missouri, asphalts in, see "asphalts" 
Mixed-base petroleum,- see "petroleum" 
Mixers, 350, 372 

Mixtures of bituminous substances: 
binary, see "binary mixtures" 
complex, see "complex mixtures" 
tertiary, see "tertiary mixtures" 
Moh's hardness scale, 495 



598 



SUBJECT INDEX 



Moisture, see "water" 
Moisture, effect on: 

bituminized fabrics, 438, 563 

bituminized mineral aggregates, 552 

bituminized substances, 576 
Montan wax, 79, 161, 205, 207 

classification of, 26 

for electrical insulation, 81 

in Saxony, 80 

properties of, 340, 482 

weather-resistance of, 340 
Moulding compositions, 452 
Muckite, 59 
Mullen strength of: 

burlap or duck, 569 

felt, 390, 569 

paper, 436, 438 
Multiple shingle strip, see "shingle strip" 
Mummies, 5, 11, 12 

N 
Naphtha from: 

coal tar, table facing 245, 248, 465, 466 

lignite tar, 211, 213 

peat tar, 201 

petroleum, 267, 277, 279, 280, 281, 282, 303, 464 

shaietar, 222, 223, 
Naphtha, solubility in 88® petroleum, see "solu- 
bility" 
Naphtha, solvent, see "solvent naphtha " 
Naphtha, V. M. & P., see " V. M. & P. naphtha" 
Naphthalene, 40, 169, 227, 231, 245, 248, 481, 535 
Naphthenes, 34 
Native asphalts: 

behavior on heating, 58 

classification of, 26 

composition of, 43 

distinguishing from residual asphalts, 298, 545 

impure, 92 

metamorphosis of, 55, 57 

production in U. S., 64 

properties of, 340, 482 

pure, 82 

weather-resistance of, 340 
Native mineral waxes, see "mineral waxes" 
Natural asphalts, see "native asphalts" 
Natural gas, 25, 31 
Nebuchadnezzar on asphalt, 7 
Needle penetrometer, see "penetrometer" 
Neft-gil, 59 

Neuchatel asphalt, 13, 14, 118 
Neudorfite, 59 
Natural fats, 544 
Neutral oil, 268 

Nevada, impsonite in see "impsonite" 
New York, discovery of bituminous matter in, 

see "bituminous matter" 
New York State flash-point tester, see "flash- 
point" 
Nigeria, asphalts in, see "asphalts" 
Nigrite, 155 

Nitrogen, 42, 232, 481, 533 
Nitrogenous bodies, 42 
Nomenclature, see "terminology" 
Non-asphaltic petroleum, see "petroleum" 
Non-asphaltic pyrobitumens: 

classification of, 26 

composition of, 41, 43 

definition of, 24 

geology of, 46 



Non-asphaltic pyrobitumens — Continued: 

heating of, 58 

metamorphosis of, 58 

origin of, 58 

properties of, 22 

veins of, 50 
Non-asphaltic pj'robituminous shales, 158, 159, 

482 
Non-bituminous lignite, 204 
Non-mineral matter insoluble in carbon disul- 

phide, 526 
North America, asphalt in, see "asphalt" 
"Number" of: 

burlap, 390 

duck, 390 

felt, 389, 569 

paper, 436 



Obispo, 289 

Odor on heating, 481, 509 

Oil or oils: 

acetone, see "acetone oils" 

animal, see "animal oils" 

bone, see "bone oil" 

creosote, see "creosote oil" 

degras, see "degras oil" 

Dippel, see "Dippel oil" 

dust-laying, see "bituminous dust-laying oils" 

export, see "export oil" 

flotation, see "flotation oils" 

gas, see "gas oil" 

illuminating, see "illuminating oil" 

magma, see "magma oil" 

palm, see "palm oil" 

pine, see "pine oil" 

residual, see "residual oils" 

rosin, see "rosin oil" 

seek, see "seek oil" 

shale, see "shale tar" 

vegetable, see "vegetable oils" 

wool, see "wool oil" 
Oil-bearing shales, see "shales" 
Oil-forming shales, see "shales" 
Oil gas, 259 
Oil-gas tar, 166, 173, 259: 

classification of, 27 

distinguishing from coal tar, 262 

properties of, 262, 482 

refining of, 263 
Oil-gas-tar pitch, 263: 

classification of, 27 

distinguishing from coal-tar pitch, 264 

properties of, 263, 341, 482, 

weather-resistance of, 341 
Oilite, 162 
"Oil shales," 154, 158 

see also " pyrobituminous shales" 
Oil-water gas, 260 
Oily constituents, 547 
Oklahoma: 

asphalts in, see "asphalt" 

grahamite in, see "grahamite" 
impsonite, in, see "impsonite" 
Oklahoma asphalts: 

blown, see "blown Oklahoma asphalts" 

extraction of, see "extraction with water" 
for paving purposes, see "paving" 
Olefinacetylenes, 33 
Olefines, 32 



SUBJECT INDEX 



599 



Oleo-resin, 193 

Once-run oil, 222 

Open binder, 368 

Open-chain hydrocarbons, see "hydrocarbons" 

Orchard heating oil, 280 

Orchard oil, 268 

Orepuki shale, 164, 221 

Origin of the expression: 

asphalt, 1 

bitumen, 1 
Ornamental roofings, see "roofings" 
Osborne adhesive test, see "adhesive test" 
Oven for volatility test, 516 
Oxidation of bituminous materials, 575 
Oxidized asphalt, see "blown petroleum asphalt" 
Oxidized coal tar, 17,255,287 
Oxidized petroleum asphalt, see "blown petroleum 

asphalt" 
Oxygen, 44, 481, 534 
Oxygenated bodies, 41 

Oxygenated asphalt, see "blown petroleum as- 
phalt" 
Ozokerite, 32,74: 

classification of, 26 

discovery of, 15 

distillation of, 75 

extraction with water, 72, 75 

metamorphosis of, 56 

properties of, 75, 77, 340, 482 

weather-resistance of, 340 
Ozokerite in: 

Galicia, 76 

Rumania, 77 

Russia, 77 

Texas, 78 

United States, 77 

Utah, 66, 77 



Packages, roofing see "roofing packages" 
Packing-house grease, 327 
Packing-house pitch, 317, 332, 335 
Paints: 

air-drying, see "air-drying paints" 

analysis of, see "analysis" 

analysis of dried films, see "analysis" 

bituminous, see "bituminous paints" 

damp-proofing, see "damp-proofing paint" 

for masonry, 469 

for metal, 472 

for roofings, 470 

for wood, 472 

grinding, mill for, 469 

use by Romans, 12 

use of gilsonite in, see "gilsonite" 

use of shale-tar pitch in, 224 

weathering of, see "weathering tests" 
Palliatives, dust, see "dust palliatives" 
Palm oil, 319, 320 
Palm-oil pitch, 317, 332, 335 
Paper or papers, 436: 

electrical insulating, see "electrical insulation" 

insulating, see " insulating papers" 

sheathing, see "sheathing papers" 
Paraffinaceous mass, 2] 1, 212, 307 
Paraffinaceous petroleum, see " non-asphaltic 

petroleum" 
Paraffine, see "paraffine wax" 
Paraffine distillate, 280, 282 



Paraffine flux, 268 

Paraffine, liquid, see "liquid paraffine" 

Paraffine oil, 211, 213, 214, 268 

Paraffines, see "hydrocarbons" 

Paraffine, solid, see "solid paraffines" 

Paraffine scale, 268 

Paraffine wax: 

classification of, 27 

composition of, 32 

discovery of, 15 

from lignite tar, 208, 210, 211, 214, 307 

from peat tar, 201, 307 

from petroleum, 268, 278, 279, 281, 283, 307 

from shale tar, 223, 307 

origin of name, 15 

properties of, 309, 482 

weather-resistance of, 310, 340 
Parolite, 289 
Parrot coal, 160 
Partial combustion, 165, 172 
Particles, size of, 363, 369, 399, 540 
Pavements, 352: 

asphalt block, see "asphalt block pavements" 

asphalt mastic, see "asphalt-mastic foot pave- 
ments" 

bituminous concrete, see " bituminous concrete 
pavements" 

first asphalt block, 7 

first use in London, 15 

first use in Paris, 16 

first use in United States, 16, 17 

sheet asphalt, see "sheet asphalt pavements" 

stone-filled sheet asphalt, see "stone-filled sheet 
asphalt" 

wood-block, see "wood-block pavements" 
Paving blocks, see "asphalt block pavements" 
Paving materials, bituminous, see "bituminous 

paving materials" 
Peat, 59, 61, 197: 

bottom, see "bottom peat" 

briquetting of, 199 

classification of, 26 

dehydrating of, 199 

distillation of, 200 

earthj', see "earthy peat" 

fibrous, see "fibrous peat" 

metamorphosis of, 58, 59 

pitchy, see "pitchy peat" 

properties of, 482 

turfy, see "turfy peat" 

volatile matter in, 168 
Peat tar, 27, 166, 197, 202, 482 
Peat-tar pitch, 27, 197, 201, 203, 341, 482 
Penetration test, 495 
Penetrometer, 495 
Pensky-Martens closed flash-point tester, see 

"flash-point" 
Perilla oil, 463 

Persia, asphalt in, see "asphalt" 
Persians, use of asphalt, by 4 
Petrol, 267 
Petrolatum, 269 
Petrolenes, 527 
Petroleum: 

asphaltic, 26, 37, 265 

brightening of distillates, see "brightening" 

classification of, 26 

composition of, 32, 38, 42, 43 

continuous distillation of, 273, 274 

cracking of, 272 



600 



SUBJECT INDEX 



Petroleum — Continued : 

definition of, 23 

dehydration of, 269, 270 

destructive distillation of, 272 

dry distillation of, 272, 279, 282 

fractional distillation of, 272 

geology of, 46 

heating of, 58 

heating under pressure, 269 

intermittent distillation, 270 

mixed-base, 26, 37, 58, 265 

non-asphaltic, 26, 32, 58, 265 

paraffinaceous, see "non-asphaltic" 

products obtained from, 266 

properties of, 22, 340, 482 

refining of, 270 

settling of, 269 

steam-distillation of asphaltic, 272, 277, 278 

steam-distillation of mixed-base, 278, 280 

steam-distillation of non-asphaltic, 278, 280 

steaming of distillates, see "steaming" 

straight-distillation of, 272 

topping process of refining, see " topping proc- 
ess'' 

tower system of distilling, 273 

varieties of, 265 

weather-resistance of, 340 
Petroleum asphalts, 265: 

blown, see "blown petroleum asphalt" 

composition of, 32 

production of in U. S., 64 

refineries in U. S. producing, 266 
Petroleum distillates, 267 
Petroleum ether, 267 
Petroleum jelly, 269 
Petroleum residues, 268: 

composition of, 41 
Petroleum solvents, 464 
Petroleum spirits, 267, 464 
Petroleum springs, 48 
Petroleum tailings, 268 

Phenols, 41, 201, 214, 222, 226, 245, 248, 550 
Philippines, asphalt in, see "asphalt" 
Physical characteristics of bituminous materials, 

480 
Physical tests of bituminized fabrics, 560 
Phytocollite, 59 
Phytosteryl, 549 
Pianzite, 59 

Pigments, 393, 453, 463, 477, 539, 571 
Pine oil, 190, 465 
Pine tar, 27, 190, 191, 482 
Pine-tar pitch, 192, 482 
Pinoline, 194 
Pintsch gas, 259 
Pipe-dips, 224, 445 
Pipe-sealing compounds, 445, 447 
Pissasphaltum, 11 
Pitch: 

blast-furnace coal-tar, see "blast-furnace-coal- 
tar pitch" 

bone-fat, see "bone-fat pitch" 

bone-tar, see "bone-tar pitch" 

Burgundy, see "Burgundy pitch" 

cable, see "cable pitch" 

candle, see "candle pitch" 

cheese, see "cheese pitch" 

cholesterol, see "cholesterol pitch" 

classification of, 27 

coking, see "coking pitch" 



Pitch — Continued: 

coke-oven coal-tar, see "coke-oven coal-tar 
pitch" 

composition of, 41, 42, 43, 44 

corn-oil, see "corn-oil pitch" 

corn-oil-foots, see "corn-oil-foots pitch" 

cotton, see "cotton pitch" 

cotton-oil, see "cotton-oil pitch" 

cotton-seed-foots, see "cotton-seed-foots pitch" 

cotton-seed-oil, see " cotton-seed-oil pitch " 

cotton-stearin, see "cotton-stearin pitch" 

definition of, 24 

fat, see "fat pitch" 

fatty-acid, see "fatty-acid pitch" 

fuUer's-grease, see "fuller's-grease pitch" 

garbage, see "garbage pitch" 

gas-works coal-tar, see "gas-works coal-tar 
pitch" 

glance, see "glance pitch" 

hardwood-tar, see "hardwood-tar pitch" 

iron, see "iron pitch" 

lignite-tar, see "lignite-tar pitch" 

oil-gas-tar, see "oil-gas-tar pitch" 

packing-house, see "packing-house pitch" 

palm-oil, see "palm-oil pitch" 

peat-tar, see "peat-tar pitch" 

pine-tar, see "pine-tar pitch" 

producer-gas coal-tar, see "producer-gas coal- 
tar pitch" 

properties of, 22 

rosin, see "rosin pitch" 

seek-oil, see "seek-oil pitch" 

sewage, see "sewage pitch" 

shale-tar, see "shale tar pitch" 

stearin, see "stearin pitch" 

stearin-wool, see "stearin-wool pitch" 

Vosges, see "Vosges pitch" 

water-gas- tar, see "water-gas-tar pitch" 

wood-tar, see "wood-tar pitch" 

wool, see "wool pitch" 

wool-fat, see "wool-fat pitch" 

wool-grease, sec "wool-grease pitch" 

wurtzilite, see "wurtzilite pitch" 
Pitch coal, 59, 85 
Pitch fillers, 382 

Pitch Lake, see "Trinidad Lake" 
Pitch still, 320 
Pitchy peat, 198 
Pittsburgh flux, 269, 295 
Plastic compositions, 251, 442,473 
PhabiUty of roofing, 560, 580 
Pliability test, 444, 560 
Pliny the Elder on asphalts, 12 
Plutarch on asphalts, 11 
Polycyclic, see "hydrocarbons" 
Polymerization of bituminous substances, 56, 576 
Pontianak copal, 463 
Poole, subterranean, 48 
Portugal, asphalt in, see "asphalt" 
Pot-head compound, 450 
Power distillate, 268 

Precipitators, electrical, see "electrical precipi- 
tator" 
Preformed joints, 453 
Preformed washers, 453 
Premoulded strips, 383 
Prepared roofings, see "roofings" 
Preservatives: 

creosote, see "creosote preservatives" 

wood, seo "wood preservatives" 



SUBJECT INDEX 



GOl 



Pressed oil, 307 

Preventatives, dust, see "dust preventatives" 

Primary condensers, 230 

Primary deposit, 50 

Producer: 

Fairbanks-Morse, 241 

Korting, 201 

Loomis-Pettibone, 241 

Mond, 242 

types of, 239 

Westinghouse, 242 
Producer gas, 172, 209 
Producer-gas coal tar, 27, 166, 239, 242, 243, 

482 
Producer-gas coal-tar pitch, 27, 252, 482 
Production of: 

asphalt, see "asphalt" 

asphaltic pyrobitumens, see "asphaltic pyro- 
bitumens" 

asphaltites, see " asphaltites " 

elaterite, see "elaterite" 

gilsonite, see "gilsonite" 

grahamaite, see grahamite" 
Purifiers, 231 

Pycnometer method for specific-gravity, 488 
Pyridine, 42, 200, 226, 236, 245 
Pyrobitumen: 

asphaltic, see "asphaltic pyrobitumens" 

associated minerals, 47 

classification of, 26 

composition of, 42, 43 

definition of, 21 

geology of, 46 

non-asphaltic, see "non-asphaltic pyrobitumen" 

occurrence of, 47 

origin of, 46 

properties of, 21 
Pyrobituminous shales, 155, 158 
Pyrobituminous shales in: 

Australia, 164 

Austria, 164 

Brazil, 163 

California, 161 

Canada, 162 

Colorado, 161, 221 

England, 163 

Germany, 164 

Kentucky, 161 

Missouri, 161 

Montana, 161 

Nevada, 161 

Scotland, 163 

Spain, 164 

United States, 161, 221 

Utah, 161, 221 

"Virginia, 161 

Wyoming, 161, 221 
Pyrogenous, definition of, 21 
Pyrogenous asphalts, 27, 340 
Pyrogenous distillates, 27, 340 
Pyrogenous residues, 27, 340 
Pyrogenous waxes: 

classification of, 27 

properties of, 340 
Pyropissite, 73, 79, 160, 205, 221: 

in Saxony, 79, 205 
Pyropissitic shales, 164 
Pyroretin, 59 

Q 
QuinoUne, 42, 226, 236, 245 



R 



Rag felt, 389 

Ragusa asphalt, 123 

Rain scrubbers, 175 

Raleigh, Sir Walter, on asphalt, 12 

Ready roofings, see "roofings" 

Red oil, 211, 212 

Refikite, 59 

Refined coal tar, 251 

Refined cylinder oil, 281 

Refined paraflSne wax, 268, 309 

Refined scale wax, 309 

Refined tar, table facing 245 

Refined wax, 281 

Refining of: 

bone grease, see "bone grease" 

carcass-rendering grease, see "carcass-render- 
ing grease" 

coal tar, see "coal tar" 

corn oil, see "corn oil" 

cottonseed oil, see "cottonseed oil" 

fats and oils, see "fats and oils" 

garbage grease, see "garbage grease" 

lignite tar, see "lignite tar" 

packing-house grease, see "packing-house 
grease" 

petroleum, see "petroleum" 

refuse greases, see "refuse greases" 

sewage grease, see "sewage grease" 

shale tar, see "shale tar" 

vegetable oils, see "vegetable oils" 

water-gas tar, see "water-gas tar" 

woolen-mill w^aste, see "woolen-mill waste" 
Refractive index, 537 
Refuse greases, refining of, 327 
Reservoirs, subterranean, 48 
Residual asphalt, 268, 2"'7, 278, 280, 295: 

California grades, 299 

carelessly prepared, 296 

classification of, 27 

composition of, 43 

distinguishing characteristics, 297 

differentiating from native asphalts, 298, 545 

from asphaltic petroleum, 301 

from mixed-base petroleum, 300 

properties of, 297, 341, 482 

weather resistance of, 302, 341 
Residual oil, 268, 274, 277, 282, 283: 

classification of, 27 

composition of, 43 

from asphaltic petroleum, 283, 286 

from mixed-base petroleum, 284, 286 

from non-asphaltic petroleum, 284, 286 

mixtures with gilsonite, 129 

mixtures with grahamite, 141, 147 

properties of, 285, 340, 482 

weather-resistance of, 285, 340 
Residual pitch, see "residual asphalt" 
Residue, sulphonation, see "sulphonation 

residue" 
Residues, petroleum, see "petroleum residues" 
Residues, pyrogenous, see "pyrogenous residues' 
Residuum, 279, 282, 283 
Resin acids, 41, 543, 544 
Resins, 452, 463, 573: 

asphaltic, see "asphaltic resins" 

fossil, see "fossil resins" 
Retinasphaltum, 59 
Retinite, 59 



602 



SUBJECT INDEX 



Retort: 

construction of, 170 

Del Monte, 219 

gas-works, see "gas-works retort" 

Henderson, 219 

horizontal, see "horizontal retort" 

inclint^d, see "inclined retort" 

Pumpherton, 217 

Rolle, 206 

rosin, 193 

shale, 216 

vertical, see "vertical retort" 

Young & Fyfe, 218 
Retort lignite, 204 
Retort method of distillation, see "distillation 

test" 
Retort tar, 188 
Rhigolene, 267, 464 
Rhodesia, asphalt in, see "asphalt" 
Road binders, 251, 268 
Road oil, 268, 274, 280, 283, 285 
Rochlederite, 59 
Rock asphalt, 16, 95, 99 
Rocks, impregnated, 48 
Roll roofing, see "roofing" 
Romans, use of asphalt paints by, 12 
Roofing or roofings, 386: 

analysis of, 564 

built-up, 419 

color of, 580 

discovery of, 14 

fastening devices for, 415 

laminated, 408 

laying, 418 

multiple-layered, see "laminated" 

ornamental, 410 

pliability of, see "pliability test" 

production of, 425 

single-layered, 398 

tensile-strength of, see "tensile strength" 

testing of, 560 

types of, 560 

weathering tests of, 577 
Roofing cleats, 416 
Roofing fabrics, 386 
Roofing felt, 387 
Roofing packages, 417 
Roofing shingles, see "shingles" 
Rosin, 193, 341, 452, 463, 551, 573 
Rosin esters, 463, 475 
Rosin oils, 190, 194, 465, 551 
Rosin pitch, 27, 193, 195, 341, 482 
Rosin spirits, 190, 194, 195, 465 
Rosin varnish, 573 
Rubber, 448, 452 

Rubber substitutes, see "bituminous rubber sub- 
stitutes" 
Rumania, ozokerite in, see "ozokerite" 
Russia: 

asphalt in, see "asphalt" 

ozokerite in, see "ozokerite" 



?and, 363, 401, 540 

Sandarac, 463 

Saponifiable constituents, 481, 542 

Saponifiable matter, 542, 547 

Saponification olein, 320 

Saponification stearin, 320 

Saponification value, 544 



Sarco, 289 

Saturated hydrocarbons, 30, 481, 537 
Saturating compositions, see "bituminous satu- 
rating compositions" 
Saturator, 404: 

asphalt, see "asphalt saturator" 

tar, see "tar saturator" 
Saxony: 

montan wax in, see "montan wax" 

pyropissite in, see "pyropissite" 
Scale wax, 268, 278, 279, 309: 

refined, see "refined scale wax" 

yellow crude, see "yellow crude scale wax" 
Scheererite, 15, 79: 

in Switzerland, 79 
Schleretinite, 59 
Schutte consistency tester, 494 
Scotland: 

hatchettite in, see "hatchettite" 

pyrobituminous shales in, see " pyrobituminous 
shales" 
Scrubbers: 

baffle, see "baffle scrubbers" 

centrifugal, see "centrifugal scrubbers" 

hurdle, see "hurdle scrubbers" 

mechanical, see "mechanical scrubbers" 

rain, see "rain scrubbers" 

static, see "static scrubbers " 
Seal-coat, 269, 357, 367 
Secondary condenser, 231 
Secondary deposit, 50 
Seconds, gilsonite, see "gilsonite" 
Sedimentation, 70 
Seek oil, 329 
Seek-oil pitch, 329 
Seepages, 48 

"Selects," gilsonite, see "giisonite" 
Semi-bituminous coal, 60 
Semi-pyrobitumens, 161 
Semi-pyrobituminous shales, 161 
SettUng tanks, 181 
Sewage grease, refining cf, 328 
Sewage pitch, 317, 332 
Sewage sludge, 328 
Seyssel asphalt, 13, 15, 116 
Shale, see "pyrobituminous shale"- 
Shale oil, see "shale tar" 
Shales: 

Albert, see "Albert shales" 

albertite, see "albertite shales" 

Arcadian, see "Arcadian shales" 

asphalt-bearing, 158 

asphaltic, see "asphaltic shales" 

asphaltic pyrobituminous, see "asphaltic pyro- 
bituminous shales" 

bituminous coal, see "bituminous coal shales" 

cannel coal, see " cannel-coal shales" 

coal, see "coal shales" 

coorongitic, see " coorongitic shales" 

distillation of, 216 

joadja, see "joadja shales" 

kerosene, see "kerosene shales" 

Kimmeridge, see "Kimmeridge shales" 

lignite, see "lignite shales" 

lignitic, see "lignitic shales" 

Lothian, see "Lothian shales" 

non-asphaltic, see " non-asphaltic pyrobitumi- 
nous shales" 

oil, see " oil shales " 

oil-bearing, 158 



SUBJECT INDEX 



603 



Shales — Continued: 

oil-forming, 158 

Orepuki, see "Orepuki shales" 

pyrobituminous, see "pyrobituminous shales" 

pyropissitic, see "pyropissitic shales" 

semi-pyrobituminous, see "semi-pyrobitumi- 
nous shales" 

stellarite, see "stellarite shales" 

wurtzilite, see "wurtzilite shales" 
Shale tar, 166, 216, 220: 

classification of, 27 

discovery of, 13 

properties of, 221, 482 

refining of, 222 
Shale-tar pitch, 216: 

classification of, 27 

discovery of, 13 

properties of, 224 
Shea butter, 319, 320 
Sheathing fabrics, 386 
Sheathing papers, 433, 560 
Sheet asphalt pavements, 367 
Sheet roofings, see "roofings" 
Sherwood oil, 267 
Shingles: 

individual, 412 

laying, 418 

prepared-roofing, 412 

strip, 414 

wide-ppaced, 414 
Shoe fillers, 454 

Sicily, asphalt in, see "asphalt" 
Sieburgite, 59 
Sieves, 540, 559 
Signal oil, 267 
Sitosteryl, 549 
Slack wax, 278, 279, 307 
Slag, examination of broken, 540 
Slaters' felt, 397 
"Slime," 6, 13 
Sludge, 278, 279, 374: 

sewage, see "sewage sludge" 
Sludge asphalt, 269, 278, 279, 303: 

classification of, 27 

composition of, 43 

distinguishing characteristics of, 305 

properties of, 304, 341, 482 

weather-resistance of, 306, 341 
Smudge oil, 268, 280 
Soap stock, 318 
S. O. binder, 289 
Softening point, 556 
Solid parafEnes, 31, 32, 481, 536 
Solubility in: 

acetone, 193, 528 

benzol, 57, 79, 528 

benzol and toluol, 528, 534 

carbon disulphide, 524 

carbon tetrachloride, 526 

petroleum naphtha (88° B6.), 527 

various solvents, 528 
Solubility test, 481, 524 
Solvent naphtha, table facing 245, 465 
Solvents, 464: 

chemical, 466 

coal-tar, 15, 464 

evaporation of, 466 

examination of, 570 

flash-point of, 464, 465, 466 

from wood, 465 



Solvents — Continued: 

petroleum, see "petroleum solvents" 
Sommer hydrometer, 489 
South America: 

asphalt in, see "asphalt" 

glance pitch in, see "glance pitch" 
Soya-bean oil, 463, 478 
Spain, asphalt in, see "asphalt" 

pyrobituminous shales in, see "pyrobituminous 
shales" 
Specifications for: 

asphalt for waterproofing, 443 

asphalt mastic floors, 375 

asphalt-saturated felt, 429 

bitulithic pavements, see "bitulithic specifica- 
tions" 

bituminous expansion joints, 384 

bituminous varnishes, 476 

coal-tar pitch for waterproofing, 442 

coal-tar saturated felt, 429 

creosote priming coat, 430 

creosote preservative for wood blocks, 379 

insulating tape, 440 

roofing felt, 390 

roofings, 424 

Topeka pavements, see "Topeka specifications" 

wooden paving blocks, 378 
Specific gravity test, 481, 486, 541: 

for bituminous matter, 486 

for mi leral aggregates, 541 
Spindle oil, 268 

Spirits, petroleum, see "petroleum spirits" 
Spirits, rosin, see "rosin spirits" 
Spontaneous hardening, 576 
Springs, 8, 48 
Static scrubbers, 174, 175 
Steam distillation, 210, 222, 246, 272, 319 
Steaming of petroleum products, 278 
Stearin, degras, see "degras stearin" 
Stearin pitch, 317 
Stearin-wool pitch, 317 
Stellarite, 155, 221 
Stellarite shales, 162 
Stills for: 

coal-tar, 247 

fatty acids, 319 

lignite, 211 

petroleum, 270 

rosin, 193 

shale tar, 222 

wurtzilite, 313 
Still grease, 223 
Still wax, 310 

Stock, candle, see "candle stock" 
Stock, soap, see "soap stock" 
Stockholm tar, 190 
Stone, examination of broken, 540: 

wax, see "wax-stone" 
Stone-filled sheet-asphalt pavement, 362 
Stove oil, 267 
Strabo on asphalt, 11 
Straight-run asphalt, 277 
Straight-run coal-tar pitch, 251 
Straw oil, 268 

Streak on porcelain, 481, 485 
Strength: 

compressive, see "compressive strength" 

Mullen, see "Mullen strength" 

of burlap or duck, 569 

of felt, 390, 569 



604 



SUBJECT INDEX 



Strength-^-C ontinued: 

of paper, 436, 438 

of roofing, 562 

tensile, see "tensile strength" 

transverse, see "transverse strength" 
Strength factor, 390, 436, 569 
Strips: 

premoulded, see " premoulded strips" 

shingle, see "shingle strips" 
Subcannel coal, 60 

Substitutes, rubber, see "bituminous rubber sub- 
stitutes" 
Suction producer, 240 
Sulphonation residue, 21, 481, 537 
Sulphur, 43, 481, 532 
Sulphurated bodies, 42 
Sulphurized asphalt, 269, 294 
Sumerians, use of asphalt by, 1 
Surface aged indoors, 481, 485 
Surface course, 361, 368, 372 
Surface mixtures, 357, 361, 366, 368 
Surfacings: 

bituminous, see "bituminous surfacings" 

of mineral matter, 394, 569, 578 

of vegetable matter, 395 
Susceptibility factor, 481, 501 
Sweater, 307 

Sweating process, 278, 307 
Switzerland: 

'asphalt" 

tee "scheererite" 



asphalt in, see 
scheererite, in, 
Syria: 

asphalt in, see "asphalt" 
glance pitch in 



"glance pitch" 



Tabbyite, 83 

Tacitus on asphalt, 11 

Tailings, wax, see "wax tailings" 

Tallow, 319, 320 

Tape, see "electrical insulating tape" 

Tar: 

boiled, see "boiled tar" 

blast-furnace, see "blast-furnace coal tar' 

bone, see "bone tar" 

browncoal, see "lignite tar" 

candle, see "candle tar" 

classification of, 27 

coal, see "coal tar" 

coke-oven, see "coke-oven coal tar" 

composition of, 41, 42, 43, 44 

definition of, 24 

dehydration, of, 180 

distillation of, see "distillation" 

effect of temperature on, 168 

gas-works, see "gas-works coal tar" 

hardwood, see "hardwood tar" 

heating of, 181, 182 

lignite, see "lignite tar" 

oil-gas, see "oil-gas tar" 

oxidized, see "oxidized coal tar" 

peat, see "peat tar" 

pine, see "pine tar" 

producer-gas, see "producer-gas coal tar" 

production of, 165 

properties of, 22, 340, 482 

retort, see "retort tar" 

separation of, 174 

shale, see "shale tar" 



Tar — Continued: 

Stockholm, see "Stockholm tar" 

water-gas, see "water-gas tar" 

weather-resistance of, 340 

wood, see "wood tar" 
Tar acids, 244, 245, 536 
Tar extractors, 180, 230, 231 
Tar filter, 180 
Tar fog, 171 
Tarred felt, 397, 429 
Tar saturator, 396 
Tar tester, 492 
Tasmanite, 158 
Tataros asphalt, 72, 121 
Temperature scales, 586 
Tensile strength: 

of bituminized aggregates, 553 

of bituminized fabrics, 438, 440, 562 

of bituminized substances, 481, 505 

of roofings, 562, 580 
Tensometer, 505 
Terminology, see "definition" 
Terpenes, 33, 37 
Tertiary mixtures, 347 
Testing of, see "analysis," also "examination": 

manufactured products, 552 

raw materials, 480 
Tests, 481 
Texaco, 289 
Texas: 

asphalt in, see "asphalt" 

grahamite in, see "grahamite" 

ozokerite in, see "ozokerite" 
Theories: 

animal, 54 

inorganic 52 

vegetable, 53 
Thermometer scales, see "temperature scales" 
Thickness factor of felt, 569 
Thickness of: 

bituminized fabrics, 562 

felt, 390, 569 

paper, 436 

roofing, 562 
Tiles, asphalt, see "asphalt tiles" 
Toluol, 39, 465, 466, 528, 534 
Topeka specifications, 364 
Topping process for petroleum, 274 
Torbanehill mineral, 160 
Torbanite, 160, 221 

Total bitumen, see "solubility in carbon disul- 
phide" 

erroneous use of expression, 21 
Tower system of distilling, see "petroleum" 
Transformer oil, 268 
Transverse strength of bituminized aggregates, 

554 
Trinidad: 

asphalt in, see "asphalt" 

grahamite in, see "grahamite" 
Trinidad asphalt, 108: 

composition of, 112 

discovery of, 12 

first use for paving purposes, 17 

production of, 115 

refining of, 113 
Trinidad lake, 12, 48, 108 
Trinidad lake asphalt, 108 
Trinidad land asphalt, 115 
Trinkerite, 59 



SUBJECT INDEX 



605 



Turpentine, 185, 189, 194, 465, 466: 

wood, see "wood turpentine" 
Turpentine substitute, 267, 464, 466 
Turfy peat, 198 
Twitchell process, 323 
Twitchell reagent, 323 

u 

Uintaite, see "gilsonite" 

Ultimate analysis, see "analysis" 

Uncombined mineral matter, see "mineral matter" 

Underwriters' Laboratories, Inc., 421 

United States: 

albertite in, see "albertite" 

asphalt consumed in, 67 

asphalt exported from, 66 

asphalt imported into, 66 

asphalt in, see "asphalt" 

bituminized matter discovered in, 16 

first pavement in, see "pavement" 

gilsonite in, see "gilsonite" 

grahamite in, see "grahamite" 

impsonite in, see "impsonite" 

ozokerite in, see "ozokerite" 

production of asphalt in, see "asphalt" 

pyrobituminous shales in, see "pyrobituminous 
shales" 

wurtzilite in, see "wurtzilite" 
Unsaponifiable matter, 481, 547 
Utah: 

albertite in, see "albertite" 

asphalt in, see "asphalt" 

gilsonite in, see "gilsonite" 

ozokerite in, see "ozokerite" 

pyrobituminous shales in, see "pyrobituminous 



wurtzilite in, see "wurtzilite" 



Vacuum distillation, 210, 246, 273, 320 

Vacuum impregnating compounds, 449 

Val de Travers asphalt, 13, 16, 17, 118 

Varnish kettle, 468 

Varnishes: 

air-drying, see "air-drying varnishes" 
baking, see "baking varnishes" 
bituminous, see "bituminous varnishes" 

Vaseline, 211, 269 

Vegetable fats, 317 

Vegetable matter, surfacings of, see "surfacings' 

Vegetableoils, 317, 325 

Vegetable oils and fats, 341, 549 

Vegetable theories, see "theories, vegetable" 

Vegetable waxes, 549 

Veins, 50 

Venezuela, asphalt in, see "asphalt" 

Venezuela lake, 48, 86 

Ventura flux, 269 

Vertical retort, 170, 227 

Viscosity test, 481, 491 

V. M. & P. naphtha, 267, 281, 464 

Voids, 363 

Volatile matter, see "volatility test" 

Volatility test, 481, 516 

Vosges pitch, 196 

W 

Walchowite, 59 

Wall-board, see "bituminized wall-board" 



Warrenite, 365 

Washers, see "scrubbers" 

Washers, preformed, see "preformed washers" 

Water, 41: 

determination of, 481, 529 
Water condensers, 174 
Water-gas, 173, 256, 257 
Water-gas tar, 166, 173: 

classification of, 27 

coefficient of expansion, 259 

property of, 259, 482 

refining of, 263 
Water-gas-tar pitch, 263: 

classification of, 27 

distinguishing from coal-tar pitch, 264 

properties of, 263, 264, 341, 482 

weather-resistance of, 341 
Waterproofing: 

asphalt for, see "asphalt" 

coal-tar pitch for, see "coal-tar pitch" 

integral, see "integral waterproofing" 

membrane, see "membrane waterproofing" 
Waterproofing compounds for: 

cement-mortar, 434, 457 

concrete, 434, 457 
Waterproofing fabrics, 386 
Waterproofing methods, 434 
Wax: 

animal, see "animal wax" 

blower, see "blower wax" 

crude scale, see "crude scale wax" 

fibrous, see "fibrous wax" 

hard, see "hard wax" 

marble, see "marble wax" 

mineral, see "mineral wax" 

montan, see " montan wax" 

paraffine, see "paraffine wax" 

pyrogenous, see "pyrogenous waxes" 

refined, see "refined wax" 

refined paraffine, see "refined paraffine wax" 

refined scale, see "refined scale wax" 

still, see "still wax" 

vegetable, see "vegetable waxes" 

white scale, see "white scale wax" 

wool, see "wool wax" 

yellow crude scale, see "yellow crude scale wax' 
Wax-stone, 75 
Wax tailings, 268, 279, 310: 

classification of, 27 

properties of, 311, 340, 482 

use as flux, 311, 343 

use in paints, 312 

weather-resistance of, 311, 340 

yield of, 282 
Wearing course, 368, 372 
Weathering tests, 574: 

of bituminized fabrics, 577 

of bituminous paints, 582 
Weight of bituminized fabric, 562 
Weiss' specific gravity method, 490 
West Africa, albertite in, see "albertite" 
West Indies, glance pitch in, see "glance pitch' 
Westphal balance, 487 

West Virginia, grahamite in, see "grahamite" 
Wheelerite, 59 
White oil, 267 
White scale wax, 281 
Wide-spaced shingles, see "shingles" 
Wood: 

distillation of, 185 



606 



SUBJECT INDEX 



Wood — Continued: 

preservation of, 378, 456 

varieties of, 185 
Wood block pavements, 378 
Wood oils, 185, 465 
Wood preservation, 16, 378, 456 
Wood tar, 166, 184: 

classification of, 27 

earliest reference to, 13 

properties of, 191, 482 
Wood-tar pitch, 184, 188, 191: 

classification of, 27 

properties of, 192, 215, 341, 482 

weather-resistance of, 193, 341 
Wood turpentine, 190: 

destructively distilled, 465 

steam-distilled, 465 
Wool degras, 329 

Woolen mill waste, refining of, 328 
Wool-fat pitch, 317, 329 
Wool grease, 317, 329, 341 
Wool-grease pitch, 317, 332 335, 336 
Wool oil, 329 
Wool pitch, 317, 329 
Wool wax, 329 
Woven fabrics, 390 
Wurtzilite, 150: 

characteristics of, 149, 161 



Wurtzilite — Continued: 

classification of, 26 

depolymerization of, 56, 313 

discovery of, 17 

in U. S., 150 

in Utah, 150 

metamorphosis of, 56 

properties of, 482 

production of, 64 
Wurtzilite asphalt, 313: 

classification of, 27 

distinguishing characteristics of, 315 

properties of 314, 341, 482 

use in paints, 316 

weather-resistance of, 316, 341 
Wurtzilite pitch, see "wurtizlite asphalt" 
Wurtzilite shales, 159 

Wyoming, pyrobituminous shales in, see "pyrO" 
bituminous shales" 



Xenophon on asphalt, 9 
Xylol, 39, 465, 466 



Yellow crude scale wax 
Yellow grease, 327 



281 



